Search Results (323)

This study aims to determine the optimal low-temperature stress relieving heat treatment that minimizes residual stresses while preserving corrosion resistance in Laser Powder Bed Fusion (L-PBF) processed Ti6Al4V alloy. Specifically, it investigates the effects of stress relieving at 400 °C, 600 °C, and 800 °C on microstructure, residual stress, and electrochemical performance. Specimens were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and electrochemical techniques. A novel microcapillary electrochemical method was employed to precisely assess passive layer stability and corrosion behaviour under simulated oral conditions, including fluoride contamination and tensile loading. Results show that heat treatments up to 600 °C effectively reduce residual stress with minimal impact on corrosion resistance. However, 800 °C treatment leads to a phase transformation from α′ martensite to a dual-phase α + β structure, significantly compromising passive film integrity. The findings establish 600 °C as the optimal stress-relieving temperature for balancing mechanical stability and electrochemical performance in biomedical and aerospace components. Full article

Donepezil (DPZ) is an Alzheimer’s disease (AD) drug that promotes cholinergic neurotransmission and exhibits excellent acetylcholinesterase (AChE) selectivity. The current oral formulations of DPZ demonstrate decreased bioavailability, attributed to limited drug permeability across the blood–brain barrier (BBB). In order to overcome these limitations, various dosage forms aimed at delivering DPZ have been explored. This discussion will focus on the nose-to-brain (N2B) delivery system, which represents the most promising approach for brain drug delivery. Intranasal (IN) drug delivery is a suitable system for directly delivering drugs to the brain, as it bypasses the BBB and avoids the first-pass effect, thereby targeting the central nervous system (CNS). Currently developed formulations include lipid-based, solid particle-based, solution-based, gel-based, and film-based types, and a systematic review of the N2B research related to these formulations has been conducted. According to the in vivo results, the brain drug concentration 15 min after IN administration was more than twice as high those from other routes of administration, and the direct delivery ratio of the N2B system improved to 80.32%. The research findings collectively suggest low toxicity and high therapeutic efficacy for AD. This review examines drug formulations and delivery methods optimized for the N2B delivery of DPZ, focusing on technologies that enhance mucosal residence time and bioavailability while discussing recent advancements in the field. Full article

Background: Oral squamous cell carcinoma (OSCC) is one of the most serious forms of cancer in the world. The opportunities to decrease the mortality rate would lie in the possibility of earlier identification of this pathology, and at the same time, the immediate approach of anticancer therapy. Furthermore, new treatment strategies for OSCC are needed to improve existing therapeutic options. Bioactive compounds found in medicinal plants could be used to support these strategies. It is already known that they have an increased potential for action and a safety profile; therefore, they could improve the therapeutic effect of classical chemotherapeutic agents in combination therapies. Methodology: This research was based on an extensive review of recently published studies in scientific databases (PubMed, Scopus, and Web of Science). The selection criteria were based on experimental protocols investigating molecular mechanisms, synergistic actions with conventional anticancer agents, and novel formulation possibilities (e.g., nanoemulsions and mucoadhesive films) for the targeted delivery of bioactive compounds in OSCC. Particular attention was given to in vitro, in vivo, translational, and clinical studies that have proven therapeutic relevance. Results: Recent discoveries regarding the effect of bioactive compounds in the treatment of oral cancer were analyzed, with a view to integrating them into oncological practice for increasing therapeutic efficacy and reducing the occurrence of adverse reactions and treatment resistance. Conclusions: Significant progress has been achieved in this review, allowing us to appreciate that the valorization of these bioactive compounds is emerging. Full article

Objectives: Colorectal cancer (CRC) is a leading cause of cancer-related mortality, driven by chronic inflammation, gut microbiota dysbiosis, and complex tumor microenvironment interactions. Current therapies are limited by systemic toxicity and poor tumor accumulation. This study aimed to develop a ROS/enzyme dual-responsive oral drug delivery system, KGM-CUR/PSM microspheres, to achieve precise drug release in CRC and enhance tumor-specific drug accumulation, which leverages high ROS levels in CRC and the β-mannanase overexpression in colorectal tissues. Methods: In this study, we synthesized a ROS-responsive prodrug polymer (PSM) by conjugating polyethylene glycol monomethyl ether (mPEG) and mesalazine (MSL) via a thioether bond. CUR was then encapsulated into PSM using thin-film hydration to form tumor microenvironment-responsive micelles (CUR/PSM). Subsequently, konjac glucomannan (KGM) was employed to fabricate KGM-CUR/PSM microspheres, enabling targeted delivery for colorectal cancer therapy. The ROS/enzyme dual-response properties were confirmed through in vitro drug release studies. Cytotoxicity, cellular uptake, and cell migration were assessed in SW480 cells. In vivo efficacy was evaluated in AOM/DSS-induced CRC mice, monitoring tumor growth, inflammatory markers (TNF-α, IL-1β, IL-6, MPO), and gut microbiota composition. Results: In vitro drug release studies demonstrated that KGM-CUR/PSM microspheres exhibited ROS/enzyme-responsive release profiles. CUR/PSM micelles demonstrated significant anti-CRC efficacy in cytotoxicity assays, cellular uptake studies, and cell migration assays. In AOM/DSS-induced CRC mice, KGM-CUR/PSM microspheres significantly improved survival and inhibited CRC tumor growth, and effectively reduced the expression of inflammatory cytokines (TNF-α, IL-1β, IL-6) and myeloperoxidase (MPO). Histopathological and microbiological analyses revealed near-normal colon architecture and microbial diversity in the KGM-CUR/PSM group, confirming the system’s ability to disrupt the “inflammation-microbiota-tumor” axis. Conclusions: The KGM-CUR/PSM microspheres demonstrated a synergistic enhancement of anti-tumor efficacy by inducing apoptosis, alleviating inflammation, and modulating the intestinal microbiota, which offers a promising stimuli-responsive drug delivery system for future clinical treatment of CRC. Full article

Background/Objectives: Denture hygiene is essential for the prevention of oral candidiasis, a condition frequently associated with Candida albicans colonization on denture surfaces. Cetylpyridinium chloride (CPC)-loaded montmorillonite (CPC-Mont) has demonstrated antimicrobial efficacy in tissue conditioners and demonstrates potential for use in antimicrobial coatings. In this study, we aimed to develop and characterize CPC-Mont-containing coating films for dentures, focusing on their physicochemical behaviors and antifungal efficacies. Methods: CPC was intercalated into sodium-type montmorillonite to prepare CPC-Mont; thereafter, films containing CPC-Mont were fabricated using emulsions of different polymer types (nonionic, cationic, and anionic). CPC loading, release, and recharging behaviors were assessed at various temperatures, and activation energies were calculated using Arrhenius plots. Antimicrobial efficacy against Candida albicans was evaluated for each film using standard microbial assays. Results: X-ray diffraction analysis confirmed the expansion of montmorillonite interlayer spacing by approximately 3 nm upon CPC loading. CPC-Mont showed temperature-dependent release and recharging behavior, with higher temperatures enhancing its performance. The activation energy for CPC release was 38 kJ/mol, while that for recharging was 26 kJ/mol. Nonionic emulsions supported uniform CPC-Mont dispersion and successful film formation, while cationic and anionic emulsions did not. CPC-Mont-containing coatings maintained antimicrobial activity against Candida albicans on dentures. Conclusions: CPC-Mont can be effectively incorporated into nonionic emulsion-based films to create antimicrobial coatings for denture applications. The films exhibited temperature-responsive, reversible CPC release and recharging behaviors, while maintaining antifungal efficacy, findings which suggest the potential utility of CPC-Mont-containing films as a practical strategy to prevent denture-related candidiasis. Full article

Background/Objectives: 5-Fluorouracil (5-FU) and Irinotecan (IRT) are two of the most used chemotherapeutic agents in CRC treatment. However, achieving treatment goals has been hampered by poor drug delivery to tumor sites and associated toxicity from off-target binding to healthy cells. Though the synergism of 5-FU-IRT has provided incremental improvements in clinical outcomes, the short elimination half-life and off-target binding to healthy cells remain significant challenges. We postulated that nanoencapsulation of a combination of 5-FU and IRT in niosomes would prolong the drugs’ half-lives, while over-encapsulation lyophilized powder in Targit^® oral capsules would passively the CRC microenvironment and avoid extensive systemic distribution. Methods: Ranges of formulation and process variables were input into design of experiment (DOE Fusion One) software, to generate screening experiments. Niosomes were prepared using the thin-film hydration method and characterized by size, the polydispersity index (PDI), morphology and intrastructure, and drug loading. Blank niosomes ranged in size from 215 nm to 257 nm. Results: After loading with the 5-FU-IRT combination, the niosomes averaged 251 ± 2.20 nm with a mean PDI of 0.293 ± 0.01. The surfactant-to-cholesterol ratio significantly influenced the niosome size and the PDI. The hydrophilic 5-FU exhibited superior loading compared to the lipophilic IRT molecules, which probably competed with other lipophilic niosome components in niosomes’ palisade layers. In vitro dissolution in biorelevant media showed delayed release until lower intestinal region (IRT) or colonic region (5-FU). Conclusions: Thus, co-nanoencapsulation of 5-FU/IRT in niosomes, lyophilization, and over-encapsulation of powder in colon-specific capsules could passively target the CRC cells in the colonic microenvironment. Full article

Xerostomia significantly compromises oral comfort, mucosal integrity, and denture retention. While topical therapies such as oral gels are commonly used to manage symptoms, their effectiveness remains limited due to an inability to replicate the complex biochemical and mechanical functions of natural saliva. This review explores the pathophysiology of salivary dysfunction, the structural and functional roles of mucins, and the tribological and rheological demands of the oral environment—particularly in denture wearers. Emphasis is placed on the interplay between mucosal surfaces, salivary films, and prosthetic biomaterials, as well as the importance of mucoadhesion and aqueous boundary lubrication. A rheological comparison of commercially available oral gels and whole human saliva (WHS) reveals that gels are significantly more viscous and elastic, yet fail to mimic the dynamic responsiveness of saliva. Current formulations lack functional standardization and labeling, limiting clinical guidance. The study proposes design principles for next-generation gels that incorporate amphiphilic, biomimetic components and measurable performance benchmarks. Full article

Background/Objectives: Dry eye disease (DED) is a multifactorial condition with complex pathophysiology involving tear film instability, ocular surface inflammation, and nerve dysfunction. This review summarizes current evidence on the different available therapies targeting these mechanisms. Methods: A review of clinical studies evaluating treatment outcomes for therapies targeting aqueous tear deficiency, Meibomian gland dysfunction, ocular surface inflammation, and ocular pain was conducted, with an emphasis on randomized controlled trials and meta-analyses where available. Results: Artificial tears provide symptomatic relief with limited impact on tear film stability. Punctal plugs improve tear retention but show variable efficacy across studies. Treatments targeting MGD—such as lipid-based lubricants, eyelid hygiene, thermal pulsation (LipiFlow, iLux), and intense pulsed light (IPL)—demonstrate improvements in gland function, though outcomes vary. Anti-inflammatory agents including cyclosporine, lifitegrast, and short-term corticosteroids improve ocular surface signs, with mixed symptom relief. Biologic therapies like autologous serum tears and platelet-rich plasma show promise for both signs and symptoms, but data remain inconsistent. Nerve-targeted therapies, including oral neuromodulators (gabapentin, antidepressants), botulinum toxin, and transcutaneous nerve stimulation, have shown potential for managing neuropathic ocular pain, although randomized data are limited. Overall, variability in study designs, patient populations, and outcome measures highlights the need for more rigorous research. Conclusions: Personalized, mechanism-based treatment strategies are essential for optimizing outcomes in DED. Future research should prioritize well-designed, controlled studies to clarify the role of emerging therapies and guide the individualized management of this heterogeneous condition. Full article

The purpose of this study was to clarify the physical durability of a diamond-like carbon (DLC) thin film coated on pure titanium. The titanium surface of the abutment does not have sufficient toughness to prevent an increase in surface roughness or damage when the implant is scaled using a professional mechanical implement. The scaling process used for the removal of the dental plaque adhered to the abutment surface could increase the potential for the deposition of oral microorganisms and the accumulation of plaque, which increase the risk of peri-implantitis. A DLC thin film is biocompatible material that is known for its toughness, including extreme hardness, high abrasion resistance, chemical inertness, and high corrosion resistance. Protecting the abutment surface with the application of a DLC might prevent plaque adhesion due to its non-stick property. There was little change in the surface roughness of titanium samples to which DLC surface protection had been applied when the surface of the sample was scratched with a stainless steel scalar more than a thousand times. When cleaning the surface of pure titanium samples, the surface roughness significantly increased. DLC thin films are effective for the prevention the surface roughness of pure titanium implants from being increased when the conventional cleaning of the surface of the implant is performed. Full article

This study aimed to develop and optimize polyvinyl alcohol (PVA)-based polymeric films containing resveratrol (RSV) and to evaluate their applicability as oral mucosal wound dressings. Given the dynamic and complex nature of the oral environment, physicochemical parameters such as elasticity, mucoadhesive strength, and the release profile of the RSV were systematically investigated. The therapeutic performance of pure resveratrol was compared with that of an extract derived from Reynoutria japonica. Films were fabricated using a solvent casting method and characterized in terms of thickness uniformity, weight, color consistency, and flexibility, all of which met the required pharmaceutical criteria. Two tested formulations, FR2 (RSV/PVA/PVP/MCA15C/NaCMC/W/PGE), FE2 (extract/PVA/PVP/MCA15C/NaCMC/W/PGE), showed the best mucoadhesive properties (261.11 ± 0.5 g for FR2 and 299.43 ± 0.38 g for FE2) and a favorable release profile both in water (72.42% for FR2, 77.23% for FE2) and in saliva (49.74% for FR2, 49.70% for FE2). Moreover, the optimized films are characterized by hydrophilicity (contact angle < 90°) and the pH value of the extract after their blurring is close to physiological, which promotes better tolerance and reduces the risk of irritation. Obtained results for polymeric films with resveratrol and R. japonica extract confirmed their great potential for use in dentistry as modern, mucoadhesive dressings, improving the effectiveness of local therapies. Full article

Background: Self-administered orally dissolving films (ODFs) encapsulating inactivated influenza vaccines represent an effective strategy for stimulating mucosal immunity. While this vaccination method offers several advantages over conventional influenza vaccines, a comparative efficacy study remains lacking. Methods: Female BALB/c mice were immunized with inactivated A/PR/8/34 (H1N1) either via orogastric inoculation or through the oral mucosal delivery using pullulan and trehalose-based ODF vaccines. Each group received equivalent antigen doses across three immunizations. Humoral responses and antibody functionality were assessed using sera collected post-immunization. After lethal viral challenge, other immunological and virological parameters were determined in corresponding tissues. Body weight and survival were monitored over a 14-day period after challenge. Results: ODF vaccination elicited significantly higher virus-specific IgA levels, HAI titers, and neutralizing antibody activity than oral gavage. After the viral challenge, ODF-immunized mice exhibited stronger IgG and IgA responses in respiratory tissues, increased antibody-secreting cells in lungs and spleen, and elevated germinal center B cells and CD8⁺ T cell responses. Both vaccination methods reduced lung pro-inflammatory cytokines and provided full protection against lethal challenge; however, the ODF group showed lower cytokine levels, better weight maintenance, and reduced viral loads. Conclusions: ODF vaccination elicits more robust systemic and mucosal immune responses than oral vaccination and may serve as a promising alternative method of influenza vaccine delivery. Full article

Aloe Vera (Aloe barbadensis Miller), a historically revered medicinal plant, has garnered great scientific attention due to its polysaccharide-rich bioactive compounds with significant therapeutic potential. This review examines the role of Aloe Vera polysaccharides as therapeutic agents in biomedical applications, highlighting their benefits as well as the risks. Traditionally recognized for its anti-inflammatory and antimicrobial effects, which are very important in wound healing, the Aloe Vera relies on its polysaccharides, which confer immunomodulatory, antioxidant, and tissue-regenerative properties. These compounds have shown promise in various applications, including skin repair, tissue engineering scaffolds, and antiviral therapies, with their delivery being facilitated via gels, thin films, or oral formulations. This review explores also their mechanisms of action and applications in modern medicine, including in the development of topical gels, dietary supplements, and innovative delivery systems such as thin films and scaffolds. Despite the promising benefits, the review addresses the possible side effects too, including allergic reactions, gastrointestinal disorders, and drug interactions, emphasizing the importance of understanding these risks for their safe clinical use. Assessing both the advantages and challenges of Aloe Vera polysaccharide medical use, this review contributes to the ongoing dialog regarding the integration of natural products into therapeutic practices, ultimately supporting informed decisions regarding their clinical application. Full article

Dental rehabilitation with titanium implants may requires the optimization of techniques and materials when oral conditions affect the successful treatment result. Thus, this study aims to customize the surface of titanium implants with bioactive vitamin D3 molecules to increase the performance of bone repair. The surfaces were functionalized following the “dip-coating” incorporation method with vitamin D3 in a solution of 1000 I.U./goat. The work was carried out in two stages: (I) physicochemical and biological tests (in vivo) in order to characterize and validate the vitamin D3 surface as well as its ability to affect peri-implant bone biomechanics; and (II) in vitro experiments to characterize viability responses, interaction and cell mineralization capacity. Scanning electron microscopy showed that the creation of vitamin D3 films is stable and homogeneous, while the in vivo results showed an increase in the biomechanical and microarchitectural capacity of the bone when vitamin D3 implants were used. Furthermore, the application of functionalized surfaces proved effective in promoting cell interaction and bone mineralization processes while preserving cell viability and capacity. In conclusion, the delivery of bioactive molecules based on vitamin D3 promotes changes in the surface microstructure of titanium, enabling an increase in the structural characteristics of bone tissue that result in an improvement in bone repair and peri-implant biomechanics. Full article

Due to advances in edible films based on polysaccharides that can carry an active pharmaceutical ingredient (API), these films now provide rapid and effective release upon consumption. These films provide an alternative to conventional drug delivery methods and are known as orally disintegrating films (ODFs). This study aimed to evaluate the capacity of an edible film composed of starch, chitosan, and maltodextrin to carry an API while maintaining its physicochemical and surface properties. Acetaminophen, a hydrophilic drug, was selected as the model API and incorporated into the edible film. The film achieved an API loading capacity of approximately 4.37 mg—comparable to the standard doses of certain hydrophilic drugs. Chemical analysis using vibrational spectroscopy revealed strong intermolecular interactions between the components. X-ray diffraction analysis confirmed these interactions through a decrease in crystallinity within the biopolymeric compounds, while the model API retained its structural ordering. However, water absorption values increased by approximately 90% in the edible film. Scanning electron microscopy images showed a homogeneous dispersion of the model API throughout the film, without aggregation, demonstrating that the film can effectively accommodate this drug concentration. Furthermore, the elasticity remained comparable in both formulations, with a Young’s modulus of 9.27 MPa for the control film and 9.38 MPa for the API-loaded film. Overall, the edible film developed in this study represents a promising system for API delivery. Full article

Bacterial infections caused by resistant strains have emerged as one of the most significant life-threatening challenges. Developing alternatives to conventional antibiotic formulations is crucial to overcoming these challenges. Vancomycin HCl (VCM) is a glycopeptide antibiotic used for Gram-positive bacterial infections that must be given intravenously for systemic infections since it cannot pass through the gut wall due to its chemical structure and characteristics. The aim of this research is to develop VCM in a niosomal nanoform to then be encapsulated in fast-disintegrating oral films for effective delivery to enhance the application of vancomycin-loaded niosomes for treating oral infections and to be used in dental treatments. The formulation of niosomes encapsulating VCM was conducted with various ratios of Span 40, Span 60, and cholesterol as well as Kolliphor RH40 and Kolliphor ELP as co-surfactants using the microfluidic technique. The prepared niosomes were characterised using dynamic light scattering (DLS) for their size determination; high-pressure liquid chromatography, HPLC, for drug encapsulation efficiency determination; and the agar diffusion method for the determination of the antibacterial efficacy of the VCM niosomes against Bacillus subtilis. The niosomal formulation was then incorporated into polyvinyl alcohol (PVA) film, and the properties of the oral film were characterised by in vitro assays. The vancomycin-loaded niosomes produced with optimal conditions exhibited small diameter with acceptable polydispersity index, and drug encapsulation efficiency. This study presents multifunctional niosomes loaded with VCM, which demonstrated efficient in vitro activity against Gram-positive bacteria upon the slow release of VCM from niosomes, as demonstrated by the dissolution test. Oral films containing VCM niosomes demonstrated uniform weights and excellent flexibility with high foldability and a rapid disintegration time of 105 ± 12 s to release the niosomal content. This study showed that the microfluidic approach could encapsulate VCM, a peptide in salt form, in surfactant-based niosomal vesicles with a narrow size distribution. The incorporation of niosomes into fast-disintegrating film provides a non-invasive and patient-friendly alternative for treating bacterial infections in the oral cavity, making it a promising approach for dental and systemic applications. Full article