Development of Sustainable Hydrophilic Azadirachta indica Loaded PVA Nanomembranes for Cosmetic Facemask Applications

Nanofiber-based facial masks have attracted the attention of modern cosmetic applications due to their controlled drug release, biocompatibility, and better efficiency. In this work, Azadirachta indica extract (AI) incorporated electrospun polyvinyl alcohol (PVA) nanofiber membrane was prepared to obtain a sustainable and hydrophilic facial mask. The electrospun AI incorporated PVA nanofiber membranes were characterized by scanning electron microscope, Ultraviolet-visible spectroscopy (UV-Vis) drug release, water absorption analysis, 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging, and antibacterial activity (qualitative and quantitative) at different PVA and AI concentrations. The optimized nanofiber of 376 ± 75 nm diameter was obtained at 8 wt/wt% PVA concentration and 100% AI extract. The AI nanoparticles of size range 50~250 nm in the extract were examined through a zeta sizer. The water absorption rate of ~660% and 17.24° water contact angle shows good hydrophilic nature and water absorbency of the nanofiber membrane. The UV-Vis also analyzed fast drug release of >70% in 5 min. The prepared membrane also exhibits 99.9% antibacterial activity against Staphylococcus aureus and has 79% antioxidant activity. Moreover, the membrane also had good mechanical properties (tensile strength 1.67 N, elongation 48%) and breathability (air permeability 15.24 mm/s). AI-incorporated nanofiber membrane can effectively be used for facial mask application.


Introduction
Human skin comprises three-layered structures: the hypodermis, the dermis, and the epidermis [1]. The epidermal layer is the outermost layer exposed to the external environment and microbes for an extended period, imparting its aesthetics [2]. Propionibacterium acnes is the primary bacteria responsible for acne and pimples [3] on the face, which can be eliminated with natural antibacterial agents [4]. Initially, clay was used to overcome these flaws; however, poor penetration of the ingredient to the skin lowered its efficiency [5]. Other skincare products in use include creams, lotions, emulsifiers, and facemasks, the latter being the most likely. It functions as skin food, allowing the epidermal layer to heal composite nanofiber sheet of Polyvinyl Pyrrolidone/polycaprolactone (PVP/PCL) loaded with tea tree oil was developed with an electrospinning technique. The developed sheets possess effective antibacterial activity against Staphylococcus aureus and Escherichia coli (7.5 and 9.55 mm zone of inhibition), with up to 61% of antioxidant activity [43].
A few studies have been conducted with natural ingredients loaded on nanofibers for skin application. However, limited study has been explored on synthesizing AIincorporated PVA nanofiber with effective and fast AI extract release. This research suggests an effective way to incorporate AI extract in PVA nanofiber during electrospinning, along with control release of AI extract when applying nanofiber membrane as a facial mask.
In this work, we prepared AI integrated PVA electrospun nanofiber membrane for a biocompatible facial mask. Nanofiber membranes based on different PVA and AI extract concentrations have been prepared through needless electrospinning. AI extract is integrated into nanofiber as a natural antibacterial agent, exhibiting effective antibacterial activity on the skin. Moreover, PVA is also a biopolymer and is recognized as a safe ingredient by the Food and Drug Authority, United States of America [44], providing a sustainable solution for various biomedical applications [45]. Fiber morphology and functional groups of nanofiber membrane were analyzed through the scanning electron microscope (SEM) and Fourier-transform infrared spectroscopy (FTIR). The AI extract release of the composite membrane has been analyzed through the UV-Vis spectrophotometer. The nanofiber membrane's water absorption and contact angle have been estimated to evaluate the moisture management of the nanofiber membrane. The antibacterial activity and antioxidant characteristics are analyzed to calculate the functionality of the AI-incorporated PVA nanofiber membrane. Due to its effective drug release, biocompatibility, and porous structure, the as-prepared nanofiber can be used as a facial mask.

Materials
Polyvinyl alcohol (PVA) of Mw~85,000-124,000 (99% hydrolyzed) and High-Performance Liquid Chromatography (HPLC) grade water were purchased from Sigma Aldrich, Taufkirchen, Germany. 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ethanol were purchased from the local supplier of Alfa Aesar, Haverhill, MA, USA. Fresh leaves of AI were obtained from the biological gardens of The University of Agriculture in Faisalabad, Pakistan.

Extraction of AI Juice
The extraction of juice began with the collection of AI leaves. After thorough washing, the leaves were air-dried at room temperature for two hours. Then, the leaves were passed through a juicer machine and a strainer cloth to obtain juice which further passed through multiple stages of fine filtration processes. The filtered juice of AI was used purely as a solvent to dissolve the polymer in the case of samples with 100:0 AI concentration. However, the other samples, 75:25 (8P-75E) and 50:50 (8P-50E), were prepared through dilution of pure AI extract with HPLC water to get the required ratio.

Preparation of Electrospinning Solution
Electrospinning solutions were prepared by dissolving three PVA concentrations (6, 7, and 8 wt./wt.%) in a mixture of AI extract and HPLC water with different ratios, respectively. The concentration of AI extract was adjusted to 100:0 wt.%, 75:25 wt.%, and 50:50 wt.% of the solvent. These solutions were prepared with constant stirring at 600 rpm for 24 h at 60 • C. Figure 1 illustrates the process flow of the prepared nanofibers facemask, starting from the AI extraction from fresh leaves and solution preparation with PVA polymer. Subsequent electrospinning of PVA/AI extracts solution at needleless electrospinning setup (Elmarco Nanospider NSLAB, Liberec, Czech Republic, one spinning electrode, small Membranes 2023, 13, 156 4 of 18 carriage capacity 10 mL, spinning voltage 0-80 kV, and spinning distance 120-240 mm). After multiple trials, the process variables, such as applied voltage, spinning distance, and carriage speed, were held constant at 45 kV, 20 cm, and 25 mm/s, respectively. All solutions were run for 8 h to fabricate separate nanofiber sheets of 0.2 mm thickness. Environmental conditions (temperature 28 ± 2 • C and relative humidity 45 ± 3% R.H) were kept constant throughout the electrospinning process. The following combinations of membranes with three levels of PVA and AI extract were fabricated to analyze the impact of the PVA and AI extract concentration on the functional characteristics of the nanofibrous membrane, as given in Table 1.

Characterization and Techniques
SEM (MIRA 3 TESCAN, Kohoutovice, Czech Republic) was used to investigate the produced nanofibers' fiber morphology. ImageJ software was used to analyze the diameter of prepared samples. The diameter of 100 fibers was recorded, and then the average diameter was calculated. Fourier transform infrared (FTIR) technique was used to investigate the functional group of the prepared AI-incorporated PVA-nanofibers membrane with an over a range of 400-4000 cm −1 . It was performed on PERKIN ELMER Spectrum 2 (Waltham, MA, USA).
The particle size distribution of AI particles was determined by Zeta Sizer (Ver 7.11, Malvern, UK) using the dynamic light scattering (DLS) approach. The solution was sonicated in the water bath to prevent particle aggregation and disperse particles within the solution before the test. Single fiber tensile tester machine UTM-4 (Sonnenbergstrasse, Switzerland) measured tensile force and elongation at the break of prepared nanofibers according to standard ASTM D882-01. The sample size for testing was 5 mm × 50 mm. Each sample was tested five times, and the average was calculated. The air permeability of the developed nanofibers was measured on SDL ATLAS M-021A (Rock Hill, SC, USA) according to standard ISO-9237. The testing parameters were kept at 100 Pa pressure with a 20 cm head. Each sample was measured five times, and the average value was recorded. Each sample of nanofiber sheet was measured for its water contact angle (WCA) to confirm its hydrophilicity. The optical tensiometer (Theta lite/TL-100, Espoo, Finland) measured WCA via the sessile drop method. A sample with 1 × 1-inch dimensions was put on the sample tray, and the water was dropped onto the sheet's surface. After monitoring the contact angle for 12 s, the machine recorded a final reading. The developed nanofiber membrane was cut into 2.5 cm × 2.5 cm pieces, and its dry weight, or Wd, was noted at room temperature (30 °C and 55% R.h). After that nanofiber sheet was placed in PBS (0.01

Characterization and Techniques
SEM (MIRA 3 TESCAN, Kohoutovice, Czech Republic) was used to investigate the produced nanofibers' fiber morphology. ImageJ software was used to analyze the diameter of prepared samples. The diameter of 100 fibers was recorded, and then the average diameter was calculated. Fourier transform infrared (FTIR) technique was used to investigate the functional group of the prepared AI-incorporated PVA-nanofibers membrane with an over a range of 400-4000 cm −1 . It was performed on PERKIN ELMER Spectrum 2 (Waltham, MA, USA).
The particle size distribution of AI particles was determined by Zeta Sizer (Ver 7.11, Malvern, UK) using the dynamic light scattering (DLS) approach. The solution was soni-cated in the water bath to prevent particle aggregation and disperse particles within the solution before the test. Single fiber tensile tester machine UTM-4 (Sonnenbergstrasse, Switzerland) measured tensile force and elongation at the break of prepared nanofibers according to standard ASTM D882-01. The sample size for testing was 5 mm × 50 mm. Each sample was tested five times, and the average was calculated. The air permeability of the developed nanofibers was measured on SDL ATLAS M-021A (Rock Hill, SC, USA) according to standard ISO-9237. The testing parameters were kept at 100 Pa pressure with a 20 cm head. Each sample was measured five times, and the average value was recorded. Each sample of nanofiber sheet was measured for its water contact angle (WCA) to confirm its hydrophilicity. The optical tensiometer (Theta lite/TL-100, Espoo, Finland) measured WCA via the sessile drop method. A sample with 1 × 1-inch dimensions was put on the sample tray, and the water was dropped onto the sheet's surface. After monitoring the contact angle for 12 s, the machine recorded a final reading. The developed nanofiber membrane was cut into 2.5 cm × 2.5 cm pieces, and its dry weight, or W d , was noted at room temperature (30 • C and 55% R.h). After that nanofiber sheet was placed in PBS (0.01 M, pH 4.9-5.1) for different intervals of time (1, 3, 5, and 10 min), and the weight was recorded as W w after the extra water was wiped with a filter paper (blotted). The calculation for the water absorption rate was as follows in Equation (1).
Antioxidant tests for AI-loaded PVA nanofibers were conducted using a modified version of the DPPH radical scavenging assay described previously. An equal amount of PVA nanofibers integrated with AI immersed in a 3 mL ethanol-based DPPH solution of 10 −4 M. Samples were kept at room temperature in the darkness for 60 min. Afterward, at 517 nm, the samples' absorbance was measured using a UV-Vis spectrophotometer (Perkin Elmer, Waltham, MA, USA). The percentage of antioxidant activity was determined using the following Equation (2).
Radical Scavenging %age = (Abs cnt − Abs smp) Abs cnt × 100 The sample of AI extract containing PVA nanofiber sheets was placed at 37 • C in 10 mL of potassium buffer solution (PBS, pH 4.9). At predefined intervals, 1 mL of each PBS was removed for additional analysis and substituted with 1 mL of PBS to maintain the release. UV-Vis spectrophotometer (Perkin Elmer, Model # λ 950) was set at a wavelength of 410 nm and used to study in vitro drug release. The calibration curve for AI extract was then used to convert the obtained absorbance into a concentration. Skin patch testing was performed at the Pakistan Council of Scientific and Industrial Research (PCSIR) site in Lahore. The skin patch testing was conducted in accordance with the Declaration of Helsinki, and approved by Ethics Review Committee at the Office of Research Innovation and Commercialization at National Textile University (AC/ORIC/20-43, 7 December 2021). Small patches of the created nanofibers were applied to sensitive areas (near the armpit) of the volunteer's skin and monitored for irritation, sensitivity, and redness [46,47]. The sample size of 2.5 × 2.5 inches was placed in the armpit area of 30 volunteers (age group 25 to 40) and analyzed for various time intervals (10 min, 30 min, 1 h, 2 h, and 4 h) for skin patch testing as cited in the literature [48] and the number of volunteers varies according to the research study.
The antibacterial activity of the developed nanofibers was evaluated to check the efficacy against bacteria and the effect of PVA percentage and AI concentration on the bacteria by Agar disc diffusion test (qualitative) & Colony-forming unit (CFU) test (quantitative). In CFU, samples with varied AI concentrations (AI-50%, AI-75%, and AI-100%) having constant PVA percentage (8% wt/wt), and samples with varied PVA percentages (PVA-6%, PVA-7%-, and PVA-8%) with the same AI concentration (100% AI) were placed in a flask Membranes 2023, 13, 156 6 of 18 containing bacterial colonies. These flasks are then placed in a wrist shaker at 250 rpm overnight. Each flask underwent overnight shaking before being serially dissolved and placed in the incubator at 37 • C. The relative percentage of bacterial colonies was calculated from the flask with the test sample and the flask without the test sample. For the qualitative test, the antibacterial activity of samples was checked against the bacteria S. aureus samples (AI-50%, AI-75%, and AI-100%) and (PVA-6%, PVA-7%-, and PVA-8%) placed in Petri dishes with bacteria. Each sample's zone of inhibition was assessed after the Petri dishes had been in the incubator for 24 h at 37 • C.

Surface Morphology
SEM analyzed all the optimized samples with different AI and PVA concentrations for surface morphology. Results showed that fibers are smooth, and no beaded structure is present in these samples, as shown in Figures 2 and 3. The diameters of developed nanofibers are 283 ± 54, 329 ± 83, and 376 ± 75 nm for 6, 7, and 8 wt/wt% of PVA, respectively, while using the 100% AI extract, as presented in Figure 2. The PVA concentration has a direct relation and significant impact on the diameter of the nanofibers. The increases in the PVA concentration increased the nanofiber diameter, as a higher concentration of polymer enhances the entanglement of molecular chains, increasing the spinning solution's viscosity. Hence the greater viscosity of the polymer solution leads to the formation of coarser nanofiber, having a greater nanofiber diameter. While at low polymer concentration, molecular entanglement is minimized, resulting in a less dense solution, and fibers with fine diameters are formed [49]. The histogram of nanofiber diameter at different PVA concentrations reveals that nanofibers with uniform diameter distribution were obtained at 8%, with a maximum load of the active agent by using 100% AI extract as solvent. viscosity. Hence the greater viscosity of the polymer solution leads to the formation of coarser nanofiber, having a greater nanofiber diameter. While at low polymer concentration, molecular entanglement is minimized, resulting in a less dense solution, and fibers with fine diameters are formed [49]. The histogram of nanofiber diameter at different PVA concentrations reveals that nanofibers with uniform diameter distribution were obtained at 8%, with a maximum load of the active agent by using 100% AI extract as solvent.  Figure 3 indicates the influence of the AI extract on the diameter of the PVA nanofibers at different AI/water ratios of 50:50, 75:25, and 100:0, whereas the PVA concentration is kept constant at 8 wt. The mean diameter is noted as 384 ± 83, 380 ± 76, and 376 ± 75, respectively, for the AI/water ratio 50:50, 75:25, and 100:0. The histogram of all the samples with different AI/water ratio reveals the uniform nanofiber diameter distribution. Hence, the impact of the AI/Water ratio on the nanofiber diameter is not as significant as PVA concentration, and no defined relation is noted between AI/Water ratio and nanofiber diameter.

Chemical Composition through FTIR & Particle Size and Distribution
The FTIR Spectra of pristine PVA nanofibers, AI extract, and AI-incorporated PVA nanofibers are shown in Figure 4a. In PVA nanofiber, the broad transmittance peak at 3302 cm −1 is assigned to the hydroxyl group (O-H), the characteristic peak of pristine PVA nanofibers [26]. The peaks at 2917 cm −1 and 2848 cm −1 represent the asymmetric and symmetric CH2 stretching [50]. Due to the existence of unalcoholized acetyl groups, the peak around 1728 cm −1 was referred to be the result of carbonyl (C=O) stretching [51,52]. The presence of -CH2, -CH3, and C-O vibrational stretching is shown by the peaks at 1425 cm −1 , 1368 cm −1 , and 1087 cm −1 , respectively. [53]. In the IR spectrum of AI extract solution, the characteristic peaks at 3365 cm −1 and 2917 cm −1 are ascribed to stretching of O-H and vibrational bending of amine (N-H) groups due to polyols [54]. The peak at 1591 cm −1 is attributed to the C=C stretching of the alkene group, while the peak at 1118 cm −1 corresponds to the C-O stretching of triglyceride content of natural AI [55]. After blending AI extract with PVA, noticeably changed peaks have been observed in the PVA + AI nanofiber sheet spectrum. The peaks at 3267 cm −1 and 2917 cm −1 are ascribed to the O-H and N-H overlapping. The peak at 1585 cm −1 represents C=C stretching due to the alkane group in the structure of AI [56]. DLS result indicates the particle size distribution histogram in the range of ~50 nm to ~255 nm, as shown in Figure 4b, having the average particle/ingredients size of 123 nm [57]. This result indicates that AI nanoparticles can easily be incorporated into nanofiber sheets.  The mean diameter is noted as 384 ± 83, 380 ± 76, and 376 ± 75, respectively, for the AI/water ratio 50:50, 75:25, and 100:0. The histogram of all the samples with different AI/water ratio reveals the uniform nanofiber diameter distribution. Hence, the impact of the AI/Water ratio on the nanofiber diameter is not as significant as PVA concentration, and no defined relation is noted between AI/Water ratio and nanofiber diameter.

Chemical Composition through FTIR & Particle Size and Distribution
The FTIR Spectra of pristine PVA nanofibers, AI extract, and AI-incorporated PVA nanofibers are shown in Figure 4a. In PVA nanofiber, the broad transmittance peak at 3302 cm −1 is assigned to the hydroxyl group (O-H), the characteristic peak of pristine PVA nanofibers [26]. The peaks at 2917 cm −1 and 2848 cm −1 represent the asymmetric and symmetric CH 2 stretching [50]. Due to the existence of unalcoholized acetyl groups, the peak around 1728 cm −1 was referred to be the result of carbonyl (C=O) stretching [51,52]. The presence of -CH 2 , -CH 3 , and C-O vibrational stretching is shown by the peaks at 1425 cm −1 , 1368 cm −1 , and 1087 cm −1 , respectively [53]. In the IR spectrum of AI extract solution, the characteristic peaks at 3365 cm −1 and 2917 cm −1 are ascribed to stretching of O-H and vibrational bending of amine (N-H) groups due to polyols [54]. The peak at 1591 cm −1 is attributed to the C=C stretching of the alkene group, while the peak at 1118 cm −1 corresponds to the C-O stretching of triglyceride content of natural AI [55]. After blending AI extract with PVA, noticeably changed peaks have been observed in the PVA + AI nanofiber sheet spectrum. The peaks at 3267 cm −1 and 2917 cm −1 are ascribed to the O-H and N-H overlapping. The peak at 1585 cm −1 represents C=C stretching due to the alkane group in the structure of AI [56].

Mechanical Properties and Air Permeability Testing
Tensile force and elongation at break were examined to analyze the mechanical properties of the nanofiber membrane. The effect of PVA concentration on mechanical strength has been noted, and the results are shown in Figure 5a. It can be noted that as the PVA concentration is decreased, mechanical strength is also reduced. This is because PVA tends to form nanofibers with finer diameters at lower concentrations. Additionally, during electrospinning, the larger percentage of solvent in the mixture tends to evaporate, leaving the polymer. Thus, the mechanical characteristics of electrospun PVA nanofibers decreased [58]. On the other hand, when the extract concentration is changed while keeping the polymer concentration the same, tensile force and elongation do not change noticeably. This showed that extract concentration did not affect elongation and tensile force.
Eichhorn and Sampson studied the relationship between fiber diameter and the pore size of nanofiber membranes. The role of fiber diameter in controlling pore size networks is significant [59]. The effect of electrospun nanofiber membranes on various properties, such as fiber's size, and surface area diameter, was studied by Matsumoto et al. In biomedical and cosmetic applications, the open porous structure of nanofiber mats plays a vital role as it increases the effectiveness of nanofiber-based materials [60,61]. Because of a highly porous network and interconnected pores, nanofiber mats are considered ideal for such activities that provide an essential role in transporting oxygen and loaded nutrients to the skin. Figure 5c shows the air permeability of the developed electrospun nanofibers.
The result shows that the air permeability value increases as the fiber diameter increases. As the concentration of polymer increases, the gaps between the fibers also increase and vice versa, keeping the thickness of the nanofiber constant. In comparison, samples with different AI concentrations (50, 75, and 100%) show similar results because extract concentration does not affect the pore size and gaps between the nanofibers [62]. DLS result indicates the particle size distribution histogram in the range of~50 nm tõ 255 nm, as shown in Figure 4b, having the average particle/ingredients size of 123 nm [57]. This result indicates that AI nanoparticles can easily be incorporated into nanofiber sheets.

Mechanical Properties and Air Permeability Testing
Tensile force and elongation at break were examined to analyze the mechanical properties of the nanofiber membrane. The effect of PVA concentration on mechanical strength has been noted, and the results are shown in Figure 5a. It can be noted that as the PVA concentration is decreased, mechanical strength is also reduced. This is because PVA tends to form nanofibers with finer diameters at lower concentrations. Additionally, during electrospinning, the larger percentage of solvent in the mixture tends to evaporate, leaving the polymer. Thus, the mechanical characteristics of electrospun PVA nanofibers decreased [58]. On the other hand, when the extract concentration is changed while keeping the polymer concentration the same, tensile force and elongation do not change noticeably. This showed that extract concentration did not affect elongation and tensile force.
Eichhorn and Sampson studied the relationship between fiber diameter and the pore size of nanofiber membranes. The role of fiber diameter in controlling pore size networks is significant [59]. The effect of electrospun nanofiber membranes on various properties, such as fiber's size, and surface area diameter, was studied by Matsumoto et al. In biomedical and cosmetic applications, the open porous structure of nanofiber mats plays a vital role as it increases the effectiveness of nanofiber-based materials [60,61]. Because of a highly porous network and interconnected pores, nanofiber mats are considered ideal for such activities that provide an essential role in transporting oxygen and loaded nutrients to the skin. Figure 5c shows the air permeability of the developed electrospun nanofibers.
The result shows that the air permeability value increases as the fiber diameter increases. As the concentration of polymer increases, the gaps between the fibers also increase and vice versa, keeping the thickness of the nanofiber constant. In comparison, samples with different AI concentrations (50, 75, and 100%) show similar results because extract concentration does not affect the pore size and gaps between the nanofibers [62].

Hydrophobicity Study through Water Contact Angle & Swelling Behavior of the Developed Sheets
The swelling percentage of nanofibers was much higher in all the samples studied because electrospun nanofibrous mats have a highly porous nature [63] and have higher surface energy [64]. The loaded drug molecules in the samples release it much more quickly and thoroughly to the desired environment due to the increased swelling. Because they are porous and hydrophilic [65], PVA nanofibers have the highest swelling percentages ranging from ~470 to ~660% as immersion time increases [66]. The PVA chains were tightly arranged before the test because they had been dried until their mass was consistent. The solution of PBS permeated the nanofiber sheet's pore during the trial, causing into relaxing of the PVA chains [63]. Additionally, it is evident from Figure 6a,b that as PVA content rises; water absorption follows suit because PVA with higher weight percentages has more hydroxyl (-OH) groups, which increases water absorption [67].
The hydrophilicity and hydrophobicity of polymeric nanofibers play a significant role in practical applications [68]. Figure 6c illustrates the results of water droplet contact angle measurements on electrospun AI-PVA nanofiber surfaces. PVA's hydrophilic nature demonstrates that as the PVA percentage increases, the (-OH) groups increase,

Hydrophobicity Study through Water Contact Angle & Swelling Behavior of the Developed Sheets
The swelling percentage of nanofibers was much higher in all the samples studied because electrospun nanofibrous mats have a highly porous nature [63] and have higher surface energy [64]. The loaded drug molecules in the samples release it much more quickly and thoroughly to the desired environment due to the increased swelling. Because they are porous and hydrophilic [65], PVA nanofibers have the highest swelling percentages ranging from~470 to~660% as immersion time increases [66]. The PVA chains were tightly arranged before the test because they had been dried until their mass was consistent. The solution of PBS permeated the nanofiber sheet's pore during the trial, causing into relaxing of the PVA chains [63]. Additionally, it is evident from Figure 6a,b that as PVA content rises; water absorption follows suit because PVA with higher weight percentages has more hydroxyl (-OH) groups, which increases water absorption [67]. resulting in a high affinity with water molecules, which gives nanofibers a higher moisture absorption capacity and a smaller contact angle [69]. As all samples have a contact angle of <50°, this indicates that the indigenous developed nanofibers are hydrophilic [70] and porous in structure [71].  Figure 7a,b displays the DPPH test results for the free radical scavenging activity of an AI-loaded PVA nanofiber sheet.

In Vitro Drug Release Study & Radical Scavenging Activity through DPPH
Absorbance at 517 nm decreases when antioxidant molecules neutralize DPPH free radicals, turning them into a colorless byproduct. The results indicate that the anti-oxidant activity highly depends on the extract concentration in the samples; antioxidant activity increases as the extract concentration in the samples increases, and activity decreases as the extract concentration decreases [72].
The highest value of ~79% is noted for the sample 8P-100E, followed by ~61% and ~39% for the samples 8P-75E and 8P-50E, respectively. Electrospun nanofibers and liquid AI extract were studied for their in vitro release profiles during single medium dissolution. Since the pH of facial skin is between 4-6 [73], a PBS solution with a pH of 4.9 was chosen as the medium. Figure 7c shows cumulative drug release vs. time curves for samples 100, 75, and 50% at 1, 3, 5, 10, 20, and 30 min. 8P-100E showed burst release of more than 70% of the drug within 5 min. Similarly, 8P-75E and 8P-50E showed 50% and 35% AI nanoparticles release, respectively, within the 5 min of dissolution in PBS, followed by the linear pattern of drug release over the 30 min. The difference in the drug release percentage is due to the variation of extract loaded in the samples [74]. The burst release of drug is due to the high surface-to-volume ratio of nanofibers, as nanofibers tend to lower their surface energy immediately [75], the porosity of fibers [74], and the presence of drug particles near the fiber surface during electrospinning, which facilitates drug release [76].
The DLS technique was used to investigate the size of AI particles released from the nanofiber membrane of the developed sample, and it revealed AI nanoparticles having an average size of 144 nm, as indicated in Figure 7d. The hydrophilicity and hydrophobicity of polymeric nanofibers play a significant role in practical applications [68]. Figure 6c illustrates the results of water droplet contact angle measurements on electrospun AI-PVA nanofiber surfaces. PVA's hydrophilic nature demonstrates that as the PVA percentage increases, the (-OH) groups increase, resulting in a high affinity with water molecules, which gives nanofibers a higher moisture absorption capacity and a smaller contact angle [69]. As all samples have a contact angle of <50 • , this indicates that the indigenous developed nanofibers are hydrophilic [70] and porous in structure [71]. Figure 7a,b displays the DPPH test results for the free radical scavenging activity of an AI-loaded PVA nanofiber sheet.

In Vitro Drug Release Study & Radical Scavenging Activity through DPPH
Absorbance at 517 nm decreases when antioxidant molecules neutralize DPPH free radicals, turning them into a colorless byproduct. The results indicate that the anti-oxidant activity highly depends on the extract concentration in the samples; antioxidant activity increases as the extract concentration in the samples increases, and activity decreases as the extract concentration decreases [72].
The highest value of~79% is noted for the sample 8P-100E, followed by~61% and 39% for the samples 8P-75E and 8P-50E, respectively. Electrospun nanofibers and liquid AI extract were studied for their in vitro release profiles during single medium dissolution. Since the pH of facial skin is between 4-6 [73], a PBS solution with a pH of 4.9 was chosen as the medium. Figure 7c shows cumulative drug release vs. time curves for samples 100, 75, and 50% at 1, 3, 5, 10, 20, and 30 min. 8P-100E showed burst release of more than 70% of the drug within 5 min. Similarly, 8P-75E and 8P-50E showed 50% and 35% AI nanoparticles release, respectively, within the 5 min of dissolution in PBS, followed by the linear pattern of drug release over the 30 min. The difference in the drug release percentage is due to the variation of extract loaded in the samples [74]. The burst release of drug is due to the high surface-to-volume ratio of nanofibers, as nanofibers tend to lower their surface energy immediately [75], the porosity of fibers [74], and the presence of drug particles near the fiber surface during electrospinning, which facilitates drug release [76].

Skin Patch Testing
The patch test is essential for identifying whether a particular cosmetic will cause an allergic or irritative reaction. The degree of response was measured by grading 0, +, ++, +++ for non-allergic, weak/low allergic, moderate allergic, and strong allergic, respectively [77]. The results written in Table 2 indicated no redness, irritation, or sensitivity, suggesting that the produced nanofiber sheet can be used safely on human skin [78].

In Vitro Antimicrobial Activities
Bacterium is the primary cause of acne and pimples on the face, and S. aureus is one of the significant bacterias for acne [79]. Figures 8a,b and 9a,b shows the visual representation of the samples' qualitative and quantitative samples results against the S. aureus bacteria, respectively. Figure 8c shows the qualitative results that as the polymer concentration increases from 6% to 8%, the zone of inhibition changes unnoticeably from 9.6 mm The DLS technique was used to investigate the size of AI particles released from the nanofiber membrane of the developed sample, and it revealed AI nanoparticles having an average size of 144 nm, as indicated in Figure 7d.

Skin Patch Testing
The patch test is essential for identifying whether a particular cosmetic will cause an allergic or irritative reaction. The degree of response was measured by grading 0, +, ++, +++ for non-allergic, weak/low allergic, moderate allergic, and strong allergic, respectively [77]. The results written in Table 2 indicated no redness, irritation, or sensitivity, suggesting that the produced nanofiber sheet can be used safely on human skin [78].

In Vitro Antimicrobial Activities
Bacterium is the primary cause of acne and pimples on the face, and S. aureus is one of the significant bacterias for acne [79]. Figure 8a,b and Figure 9a,b shows the visual representation of the samples' qualitative and quantitative samples results against the S. aureus bacteria, respectively. Figure 8c shows the qualitative results that as the polymer concentration increases from 6% to 8%, the zone of inhibition changes unnoticeably from 9.6 mm to 9.8 mm, indicating that the change in polymer percentage does not affect the inhibition zone. In comparison, as the AI concentration increased from 50% to 100% in the samples, the inhibition zone expanded from 7.1 mm to 9.8 mm, demonstrating that increasing AI concentration enhances antibacterial properties [80].
Membranes 2023, 13,156 13 of 19 to 9.8 mm, indicating that the change in polymer percentage does not affect the inhibition zone. In comparison, as the AI concentration increased from 50% to 100% in the samples, the inhibition zone expanded from 7.1 mm to 9.8 mm, demonstrating that increasing AI concentration enhances antibacterial properties [80].
In the quantitative antibacterial efficiency test, results are shown in Figure 8d. They indicated that as the concentration of AI increased in the samples from 50 to 100%, the efficiency percentage increased from 97.2 to 99.9%, showing that the AI extract concentration had an effect on the antibacterial efficiency. However, data showed that increasing the PVA percentage in the samples from 6 to 8 percent did not mitigate or improve the sample's antibacterial effectiveness, indicating that the antibacterial effectiveness was independent of the PVA wt. (%) of the sample [81].   In the quantitative antibacterial efficiency test, results are shown in Figure 8d. They indicated that as the concentration of AI increased in the samples from 50 to 100%, the efficiency percentage increased from 97.2 to 99.9%, showing that the AI extract concentration had an effect on the antibacterial efficiency. However, data showed that increasing the PVA percentage in the samples from 6 to 8 percent did not mitigate or improve the sample's antibacterial effectiveness, indicating that the antibacterial effectiveness was independent of the PVA wt. (%) of the sample [81].

Conclusions
In this study, a biocompatible electrospun AI-integrated PVA nanofiber mask for facial skin remediation was developed. The composite nanofiber sheet comprises PVA nanofibers as carriers and AI nanoparticles as antibacterial skin agents. SEM images confirmed the fabrication of uniform nanofibers with a diameter from 282 to 375 nm at a 6-8% polymer percentage. The optimized nanofiber membrane, having a diameter of 376 ± 75 nm at 8 wt% PVA with 100:0 AI/water ratio, was used to evaluate the functional characteristics. According to the FTIR analysis, the successful incorporation of AI into PVA nanofibers was confirmed by the presence of their functional groups. Based on DLS analysis, AI ingredients loaded into nanofibers ranges from 50 to 250 nm. The nanofiber sheet also possesses good air permeability of 15.24 mm/s and tensile strength of 1.67 N, which improves with an increase in PVA concentration. The WCA of 43.98 • , 22.36 • , and 17.24 • with the PVA concentration of 6, 7, and 8 wt%, respectively, indicate the hydrophilic nature of the membrane. The developed nanofiber sheets at 8% PVA of lowest WCA rapidly swelled via capillary force, reaching the highest swelling percentages of 660% after 10 min of soaking, whereas the nanofiber membrane with 6 and 7 wt% of PVA showed water absorption of 490 and 550%, respectively. The optimized nanofiber membrane also exhibits an excellent antioxidant activity of 79%, evaluated through scavenging of DPPH.
Furthermore, UV-VIS analysis shows that more than 70% of AI nanoparticles (drugs) are released in just five minutes for an optimized nanofiber membrane. The allergic patch test demonstrates that nanofibers have no adverse effects on the skin, such as redness, sensitivity, or irritation, proving their biocompatibility. The qualitative results showed the excellent antibacterial activity of the nanofiber sheet, whereas the quantitative antibacterial test confirmed its 99.9% effectiveness against S. aureus. Based on these functional characteristics, the best combination sample (8P-100E) with 8% of PVA and a 100:0 ratio of AI/water is recommended for further application/use. Hence, this innovative green AI-loaded nanofiber sheet can be applied as an effective facial mask, as demonstrated in Figure 10, delivering beneficial effects.

Conclusions
In this study, a biocompatible electrospun AI-integrated PVA nanofiber mask for facial skin remediation was developed. The composite nanofiber sheet comprises PVA nanofibers as carriers and AI nanoparticles as antibacterial skin agents. SEM images confirmed the fabrication of uniform nanofibers with a diameter from 282 to 375 nm at a 6-8% polymer percentage. The optimized nanofiber membrane, having a diameter of 376 ± 75 nm at 8 wt% PVA with 100:0 AI/water ratio, was used to evaluate the functional characteristics. According to the FTIR analysis, the successful incorporation of AI into PVA nanofibers was confirmed by the presence of their functional groups. Based on DLS analysis, AI ingredients loaded into nanofibers ranges from 50 to 250 nm. The nanofiber sheet also possesses good air permeability of 15.24 mm/s and tensile strength of 1.67 N, which improves with an increase in PVA concentration. The WCA of 43.98°, 22.36°, and 17.24° with the PVA concentration of 6, 7, and 8 wt%, respectively, indicate the hydrophilic nature of the membrane. The developed nanofiber sheets at 8% PVA of lowest WCA rapidly swelled via capillary force, reaching the highest swelling percentages of 660% after 10 min of soaking, whereas the nanofiber membrane with 6 and 7 wt% of PVA showed water absorption of 490 and 550%, respectively. The optimized nanofiber membrane also exhibits an excellent antioxidant activity of 79%, evaluated through scavenging of DPPH.
Furthermore, UV-VIS analysis shows that more than 70% of AI nanoparticles (drugs) are released in just five minutes for an optimized nanofiber membrane. The allergic patch test demonstrates that nanofibers have no adverse effects on the skin, such as redness, sensitivity, or irritation, proving their biocompatibility. The qualitative results showed the excellent antibacterial activity of the nanofiber sheet, whereas the quantitative antibacterial test confirmed its 99.9% effectiveness against S. aureus. Based on these functional characteristics, the best combination sample (8P-100E) with 8% of PVA and a 100:0 ratio of AI/water is recommended for further application/use. Hence, this innovative green AIloaded nanofiber sheet can be applied as an effective facial mask, as demonstrated in Figure 10, delivering beneficial effects.  Informed Consent Statement: Informed consent was obtained from all subjects involved in the study.
Data Availability Statement: Data will be provided on request.