Search Results (129)

Novel multifunctional fibrous materials were prepared by simultaneous dual spinneret electrospinning of two separate solutions differing in composition. This technique allowed for the preparation of materials built of two types of fibers: fibers from poly(vinyl alcohol) (PVA), chitosan (Ch), and rosmarinic acid (RA), and poly(L-lactide) (PLA) fibers containing lidocaine hydrochloride (LHC). Confocal laser scanning microscopy (CLSM) analyses showed that both types of fibers are present on the surface and in the bulk of the new materials. The presence of all components and some interactions between them were proven by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. RA and LHC were in an amorphous state in the fibers, and their presence affected the temperature characteristics and the crystallinity, as detected by differential scanning calorimetry (DSC) and X-ray diffraction analyses (XRD). The presence of PVA/Ch/RA fibers enabled the hydrophilization of the surface of the multifunctional fibrous materials (the water contact angle value was 0°). The newly developed materials demonstrated adequate mechanical properties, making them suitable for use in wound dressing applications. The RA-containing fibrous mats possessed high radical-scavenging activity (ca. 93%), and the combining with LHC led to an enhancement of this effect (ca. 98.5%). RA-containing fibrous mats killed all the pathogenic bacteria S. aureus and E. coli and decreased the titer of fungi C. albicans by ca. 0.4 log for a contact time of 24 h. Therefore, the new materials are prospective as antibacterial and atraumatic functional wound dressings, as systems for local drug delivery, and in medical skincare. Full article

This study focuses on the synthesis and characterization of thermoresponsive hydrogels of poly(lactic acid) (PLA) and poly(ethylene glycol) (PEG), PLA–PEG copolymers, aiming at the targeted and controlled release of deferoxamine (DFO), a clinically applied iron-chelating drug. Triblock (PLA-PEG-PLA) and diblock (mPEG-PLA) copolymers were synthesized using ring-opening polymerization (ROP) with five different PEGs with molecular weights of 1000, 1500, 2000, 4000, and 6000 g/mol and two types of lactide (L-lactide and D-lactide). Emulsions of the polymers in phosphate-buffered saline (PBS) were prepared at concentrations ranging from 10% to 50% w/w to study the sol–gel transition properties of the copolymers. Amongst the synthesized copolymers, only those that demonstrated thermoresponsive sol-to-gel transitions near physiological temperature (37 °C) were selected for further analysis. Structural and molecular confirmation was performed by Nuclear Magnetic Resonance (NMR) and Fourier-transform infrared spectroscopy (FTIR), while the molecular weights were determined via Gel Permeation Chromatography (GPC). The thermal transitions were studied by calorimetry (DSC) and crystallinity via X-ray diffraction (XRD) analysis. DFO-loaded hydrogels were prepared, and their drug release profiles were investigated under simulated physiological conditions (37 °C) for seven days using HPLC analysis. The thermoresponsive characteristics of these systems can offer a promising strategy for injectable drug delivery applications, where micelles serve as drug carriers and undergo in situ gelation, enabling controlled release. This alternative procedure may significantly improve the bioavailability of DFO and enhance patient compliance by addressing key limitations of conventional administration routes. Full article

Background/Objectives: The effect of fusidic acid on oral bacteria, especially on Gram- negative periodontopathogenic species, has not yet been investigated. This in vitro study aimed to analyze the antibacterial effect of fusidic acid alone and as an active component in electrospun poly(L-lactide-co-D/L-lactide) fiber fleeces. Methods: Minimal inhibitory concentrations (MIC) of fusidic acid and metronidazole (control) were determined for various oral bacteria. Eluates were collected from electrospun poly(L-lactide-co-D/L-lactide) fiber fleeces loaded with 10 and 20 wt% fusidic acid over a period of 28 d. Antibacterial activity was analyzed by means of a microdilution assay. Cytotoxicity was observed toward human gingival fibroblasts (HGFs). Results: All tested Gram-positive and Gram-negative oral bacteria were susceptible to fusidic acid. The lowest MIC was observed for Porphyromonas gingivalis (MIC < 0.062 µg/mL). Compared to the antibacterial activity of metronidazole, that of Porphyromonas gingivalis was suppressed by significant lower fusidic acid concentrations (p < 0.01). The eluates obtained from electrospun poly(L-lactide-co-D/L-lactide) fiber fleeces inhibited the growth of P. gingivalis, S. aureus, A. viscosus, and A. neslundii over a course of 28 days. The largest inhibition zones were detected for Porphyromonas gingivalis in case of the 20 wt% concentrations. The eluates were not cytotoxic toward HGFs. Conclusions: It was shown that fusidic acid has significant antibacterial potential. The results of the present investigation suggest that fusidic acid alone or delivered by electrospun fiber fleeces might be attractive for controlling oral pathogenic bacteria. Full article

Facial aging is a multifactorial and stratified biological process characterized by progressive morphological and biochemical alterations affecting both cutaneous (Layer I) and subcutaneous (Layer II) tissues. These age-related changes manifest clinically as volume depletion, tissue ptosis, and a decline in overall skin quality. In response to these phenomena, thread lifting techniques have evolved significantly—from simple mechanical suspension methods to sophisticated bioactive platforms. Contemporary threads now incorporate biocompatible polymers and hyaluronic acid (HA), aiming not only to reposition soft tissues but also to promote dermal regeneration. This review provides a comprehensive classification and critical assessment of thread lifting materials, focusing on their chemical composition, mechanical performance, degradation kinetics, and biostimulatory potential. Particular emphasis has been given to the surface integration of HA into monofilament threads, especially with the emergence of advanced delivery systems such as NAMICA, which facilitate sustained HA release. Advanced thread materials, especially those fabricated from poly(L-lactide-co-ε-caprolactone) [P(LA/CL)], demonstrate both tensile support and regenerative efficacy. Emerging HA-covered threads exhibit synergistic bioactivity, stimulating skin remodeling. NAMICA technology represents an advancement in the field, in which HA is encapsulated within biodegradable polymer fibers to enable gradual release and enhanced dermal integration. Nonetheless, well-designed human studies are still needed to substantiate its therapeutic efficacy. Consequently, the paradigm of thread lifting is shifting from purely mechanical interventions toward biologically active systems that promote comprehensive ECM regeneration. The integration of HA into resorbable threads, especially when combined with sustained-release technologies, represents a meaningful innovation in aesthetic dermatology, meriting further preclinical and clinical evaluation. Full article

This study investigates the impact of hydroxyapatite (HA) nanoparticles (NPs) on the cellular responses of poly(L-lactide-co-ε-caprolactone) (PLCL) scaffolds in bone tissue engineering applications. Three types of PLCL scaffolds were fabricated, varying in HANPs content. Saos-2 osteoblast-like cells (OBs) and THP-1-derived osteoclast-like cells (OCs) were co-cultured on the scaffolds, and cell proliferation was assessed using the MTS assay. The amount of double-stranded DNA (dsDNA) was quantified to evaluate cell proliferation. Expression levels of OBs and OCs markers were analyzed via quantitative polymerase chain reaction (qPCR) and the production of Collagen type I was visualized using confocal microscopy. Additionally, enzymatic activity of alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP or ACP5) was measured to assess OB and OC function, respectively. Interestingly, despite the scaffold’s structured character supporting the growth of the Saos-2 OBs and THP-1-derived OCs coculture, the incorporation of HANPs did not significantly enhance cellular responses compared to scaffolds without HANPs, except for collagen type I production. These findings suggest the need for further investigation into the potential benefits of HANPs in bone tissue engineering applications. Nevertheless, our study contributes valuable insights into optimizing biomaterial design for bone tissue regeneration, with implications for drug screening and material testing protocols. Full article

We report the synthesis of highly enantiopure perdeuterated poly-L-lactic acid and poly-D-lactic acid polymers with well-defined molecular weight by polymerization of perdeuterated lactides. Enantiopure D- and L-lactic acid-d₄ monomers were synthesized from sodium pyruvate-d₃ using D- and L-lactate dehydrogenase enzymes (D-LDH and L-LDH) as biocatalysts. The reduced form of the co-enzyme nicotinamide adenine dinucleotide-d₁ (NADH-d₁) was generated in situ from the oxidized form nicotinamide adenine dinucleotide (NAD⁺) by formate dehydrogenase (FDH)-catalyzed oxidation of sodium formate-d₁ to carbon dioxide with concerted reduction of NAD⁺ to NADH-d₁. For the conversion of the perdeuterated lactic acid monomers to the corresponding lactide dimers, we developed a process for generating these compounds in the high purity needed for the final anionic ring-opening polymerization step. This method enabled the generation of a range of perdeuterated polylactic acid polymers that are highly suitable for the characterization of polymer structure and dynamics using neutron scattering, infrared and nuclear magnetic resonance spectroscopy methods that are sensitive to deuterium. Furthermore, these deuterium-labeled polymers are well-suited to the study of the biodegradation of PLA-based plastics. Full article

Hyaluronic acid (HA), an integral non-sulfated glycosaminoglycan, plays a pivotal role in numerous biological functions within the extracellular matrix, crucially influencing tissue hydration and cellular activities. These findings position it as a key substance in both aesthetic interventions and regenerative medicine. This study evaluated the skin remodeling efficacy of poly(L-lactide-co-ε-caprolactone) (P(LA/CL)) threads embedded with HA particles at both the microscale (P(LA/CL)-HA-micro) and nanoscale (P(LA/CL)-HA-nano) utilizing NAMICA encapsulation technology. This investigation was conducted over a six-month period in an animal model. These threads were engineered to administer HA gradually, thereby potentially augmenting the therapeutic impacts on the skin, enhancing the bioavailability of HA, and prolonging the benefits. Methodologically, the research conformed to the ARRIVE guidelines, incorporating specific inclusion and exclusion criteria for the animal model. The threads were surgically implanted, and a series of histological indicators were evaluated at scheduled intervals to determine their influence on the structural properties of the skin. The findings indicated that both P(LA/CL)-HA-micro and P(LA/CL)-HA-nano threads demonstrated potential in skin remodeling. Notably, the P(LA/CL)-HA-nano threads may have provided some advantages in enhancing certain structural aspects of the skin. The integration of micro- and nano-HA formulations through NAMICA technology might address individual limitations and synergistically promote biorevitalization in skin remodeling. Nevertheless, the intricate interactions between the biomaterials and hosted tissue underscored in this analysis suggest that additional investigations, especially using human models, are essential to fully discern the clinical implications and refine therapeutic approaches for skin remodeling via these new technologies. Full article

Facial thread lifting with absorbable threads such as poly(L-lactide-co-ε-caprolactone) (P(LA/CL)) has been explored in an animal model. This experimental study utilized P(LA/CL)-HA-micro threads enhanced with hyaluronic acid microencapsulation via NAMICA technology in five four-month-old female pigs. The effects were compared to those of P(LA/CL)-HA threads over a six-month period through histological analysis. The results indicated improvements in skin remodeling, with P(LA/CL)-HA-micro threads enabling controlled and prolonged release of hyaluronic acid, leading to sustained improvements in tissue structure. These findings suggest that microencapsulated threads could enhance therapeutic outcomes; however, these results are preliminary and derived from an animal model. Further research and clinical trials are necessary to confirm these benefits in human subjects. Full article

In regenerative periodontal treatment, barrier membranes restore periodontal support and aid tissue healing, but slow hard tissue regeneration can disrupt healing and cause tooth instability. This study aimed to fabricate a periodontal membrane through electrospinning poly(L-lactide-co-D, L-lactide) with varying β-tricalcium phosphate (β-TCP) percentages (0%, 10%, 30%, and 40%) treated with hyaluronic acid to enhance bone regeneration in alveolar bone defects. Their ability to promote biomimetic mineralization was characterized using field emission scanning electron microscopy (FESEM) analysis, wettability, and mechanical properties. Biocompatibility and osteogenic differentiation were evaluated by examining BMSCs’ behavior. In vivo, the PLA/β-TCP membrane’s potential to promote bone regeneration was assessed through CT imaging and histological examination. FESEM analysis revealed β-TCP agglomerations within PLA fibers, increasing tensile strength. Water contact angle measurements showed better wettability and higher cell viability after hyaluronic acid treatment, indicating non-cytotoxicity. Membranes with 10% and 30% (w/w) β-TCP significantly enhanced cellular activities, including proliferation and osteogenic differentiation. Animal tests showed a significant bone growth rate increase to 28.9% in the experimental group compared to 24.9% with the commercial product Epi-Guide after three months. Overall, PLA with 30% β-TCP optimally promoted periodontal hard tissue repair and potentially enhanced bone regeneration. Full article

Biomass-based and biodegradable poly(l-lactide) (PLLA) is synthesized by ring-opening polymerization of l-lactide (LLA), for which tin(II) 2-ethylhexanoate is a major catalyst. However, the potential toxicity of tin can be a problem, especially in biomedical applications. In this study, we focused on iron, which is a non-toxic metal and an abundant resource. We investigated the ring-opening homo- and copolymerization of cyclic esters such as LLA and ε-caprolactone (CL) catalyzed by iron(III) triflate, Fe(OTf)₃, which is commercially available and known as a Lewis acid. In the polymerization of LLA in toluene at 110 °C, Fe(OTf)₃ showed relatively high activity and yielded PLLA with unimodal molecular weight distribution. The addition of 1,8-bis(dimethylamino)naphthalene (proton sponge: PS) to the Fe(OTf)₃ catalyst system increased the yield and molecular weight of the resulting polymer. In contrast, the polymerization of CL by Fe(OTf)₃ was decelerated by the presence of PS. The Fe(OTf)₃ system was found to have an exceptionally high preference for CL over LLA in the copolymerization of LLA and CL, with the reactivity ratio of r_LLA = 0.51 and r_CL = 6.9. In contrast, the Fe(OTf)₃–2PS system exhibited an LLA preference with r_LLA = 15 and r_CL = 0.22, indicating that the comonomer selectivity changed depending on the presence or absence of PS. While the LLA polymerization rate by the Fe(OTf)₃ system showed a second-order dependence on the Fe(OTf)₃ concentration, that of the Fe(OTf)₃–PS system showed a first-order dependence on the Fe(OTf)₃–PS concentration. Full article

The present work focuses on the synthesis and characterization of biobased lignin-poly(lactic) acid (PLA) composites. Organosolv lignin, extracted from beechwood, was used as a filler at 0.5, 1.0, and 2.5 wt% loadings, with ultrasonication reducing the lignin particle size to ~700 nm. The PLA–lignin composites were prepared via in situ ring-opening polymerization (ROP) of L-lactide in the presence of lignin. This method ensured uniform lignin dispersion in the PLA matrix due to grafting of PLA chains onto lignin particles, preventing aggregation. Strong polymer–filler interactions were confirmed through spectroscopic analysis (FTIR and XPS) and their effects on static and dynamic glass transitions (DSC). These interactions enhanced mechanical properties, including a two-fold increase in tensile strength and elongation at 1 wt% lignin. Crystallization was suppressed due to shorter PLA chains, and a 15% drop in dynamical fragility was observed via Broadband Dielectric Spectroscopy (BDS). Antioxidant activity improved significantly, with PLA–2.5% ultrasonicated organosolv lignin reducing DPPH• content to 7% after 8 h, while UV-blocking capability increased with lignin content. Full article

Background/Objectives: Loading of natural products into poly-(lactide-co-glycolic) acid (PLGA) nanoparticles as drug delivery systems for the treatment of diseases, such as tuberculosis (TB), has been widely explored. The current study investigated the use of PLGA nanoparticles with 7-methyljuglone (7-MJ), an active pure compound, isolated from the roots of Euclea natalensis A. DC. Methods: 7-MJ as well as its respective PLGA nanoparticles were tested for their antimycobacterial activity against Mycobacterium smegmatis (M. smegmatis), drug-susceptible Mycobacterium tuberculosis (M. tuberculosis) (H37Rv), and multi-drug-resistant M. tuberculosis (MDR11). The cytotoxicity of 7-MJ as well as its respective PLGA nanoparticles were tested for their cytotoxic effect against differentiated human histiocytic lymphoma (U937) cells. Engulfment studies were also conducted to determine whether the PLGA nanoparticles are taken up by differentiated U937 cells. Results: 7-MJ has been shown to have a minimum inhibitory concentration (MIC) value of 1.6 µg/mL against M. smegmatis and multi-drug-resistant M. tuberculosis and 0.4 µg/mL against drug-susceptible M. tuberculosis. Whilst promising, 7-MJ was associated with cytotoxicity, with a fifty percent inhibition concentration (IC₅₀) of 3.25 µg/mL on differentiated U937 cells. In order to lower the cytotoxic potential, 7-MJ was loaded into PLGA nanoparticles. The 7-MJ PLGA nanoparticles showed an 80-fold decrease in cytotoxic activity compared to free 7-MJ, and the loaded nanoparticles were successfully taken up by differentiated macrophage-like U937 cells. Conclusions: The results of this study suggested the possibility of improved delivery during TB therapy via the use of PLGA nanoparticles. Full article

We introduce a novel concept in nucleic acid delivery based on the use of mixed polymeric micelles (MPMs) as platforms for the preparation of micelleplexes with DNA. MPMs were prepared by the co-assembly of a cationic copolymer, poly(1-(4-methylpiperazin-1-yl)-propenone)-b-poly(d,l-lactide), and nonionic poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) block copolymers. We hypothesize that by introducing nonionic entities incorporated into the mixed co-assembled structures, the mode and strength of DNA binding and DNA accessibility and release could be modulated. The systems were characterized in terms of size, surface potential, buffering capacity, and binding ability to investigate the influence of composition, in particular, the poly(ethylene oxide) chain length on the properties and structure of the MPMs. Endo–lysosomal conditions were simulated to follow the changes in fundamental parameters and behavior of the micelleplexes. The results were interpreted as reflecting the specific structure and composition of the corona and localization of DNA in the corona, predetermined by the poly(ethylene oxide) chain length. A favorable effect of the introduction of the nonionic block copolymer component in the MPMs and micelleplexes thereof was the enhancement of biocompatibility. The slight reduction of the transfection efficiency of the MPM-based micelleplexes compared to that of the single-component polymer micelles was attributed to the premature release of DNA from the MPM-based micelleplexes in the endo–lysosomal compartments. Full article

Salmonid rickettsial septicemia (SRS), caused by Piscirickettsia salmonis, has been the most severe health concern for the Chilean salmon industry. The efforts to control P. salmonis infections have focused on using antibiotics and vaccines. However, infected salmonids exhibit limited responses to the treatments. Here, we developed a poly (D, L-lactide-glycolic acid) (PLGA)-nanosystem functionalized with Atlantic salmon IgM (PLGA-IgM) to specifically deliver florfenicol into infected cells. Polymeric nanoparticles (NPs) were prepared via the double emulsion solvent-evaporation method in the presence of florfenicol. Later, the PLGA-NPs were functionalized with Atlantic salmon IgM through carbodiimide chemistry. The nanosystem showed an average size of ~380–410 nm and a negative surface charge. Further, florfenicol encapsulation efficiency was close to 10%. We evaluated the internalization of the nanosystem and its impact on bacterial load in SHK-1 cells by using confocal microscopy and qPCR. The results suggest that stimulation with the nanosystem elicits a decrease in the bacterial load of P. salmonis when it infects Atlantic salmon macrophages. Overall, the IgM-functionalized PLGA-based nanosystem represents an alternative to the administration of antibiotics in salmon farming, complementing the delivery of antibiotics with the stimulation of the immune response of infected macrophages. Full article

Background/Objectives: An inhibitor of small Rho GTPase Cdc42, CASIN, has been shown to reduce cancer cell proliferation, migration, and invasion, yet it has several limitations, including rapid drug elimination and low bioavailability, which prevents its systemic administration. In this study, we designed and characterized a nanoparticle-based delivery system for CASIN encapsulated within poly(lactide-co-glycolide)-block-poly(ethylene glycol)-carboxylic acid endcap nanoparticles (PLGA-PEG-COOH NPs) for targeted inhibition of Cdc42 activity in colon cancer. Methods: We applied DLS, TEM, and UV–vis spectroscopy methods to characterize the size, polydispersity index, zeta potential, encapsulation efficiency, loading capacity, and in vitro drug release of the synthesized nanoparticles. The CCK-8 cell viability test was used to study colorectal cancer cell growth in vitro. Results: We showed that CASIN-PLGA-PEG-COOH NPs were smooth, spherical, and had a particle size of 86 ± 1 nm, with an encapsulation efficiency of 66 ± 5% and a drug-loading capacity of 5 ± 1%. CASIN was gradually released from NPs, reaching its peak after 24 h, and could effectively inhibit the proliferation of HT-29 (IC50 = 19.55 µM), SW620 (IC50 = 9.33 µM), and HCT116 (IC50 = 10.45 µM) cells in concentrations ranging between 0.025–0.375 mg/mL. CASIN-PLGA-PEG-COOH NPs demonstrated low hemolytic activity with a hemolytic ratio of less than 1% for all tested concentrations. Conclusion: CASIN-PLGA-PEG-COOH NPs have high encapsulation efficiency, sustained drug release, good hemocompatibility, and antitumor activity in vitro. Our results suggest that PLGA-PEG-COOH nanoparticles loaded with CASIN show potential as a targeted treatment for colorectal cancer and could be recommended for further in vivo evaluation. Full article