Formulation of Chitosan Stabilized Silver Nanoparticle-Containing Wound Healing Film: In Vitro and In Vivo Characterization

Chitosan alchemy: transforming tissue engineering and wound healing

Chitosan, a biopolymer acquired from chitin, has emerged as a versatile and favorable material in the domain of tissue engineering and wound healing. Its biocompatibility, biodegradability, and antimicrobial characteristics make it a suitable candidate for these applications. In tissue engineering, chitosan-based formulations have garnered substantial attention as they have the ability to mimic the extracellular matrix, furnishing an optimal microenvironment for cell adhesion, proliferation, and differentiation. In the realm of wound healing, chitosan-based dressings have revealed exceptional characteristics. They maintain a moist wound environment, expedite wound closure, and prevent infections. These formulations provide controlled release mechanisms, assuring sustained delivery of bioactive molecules to the wound area. Chitosan's immunomodulatory properties have also been investigated to govern the inflammatory reaction during wound healing, fostering a balanced healing procedure. In summary, recent progress in chitosan-based formulations portrays a substantial stride in tissue engineering and wound healing. These innovative approaches hold great promise for enhancing patient outcomes, diminishing healing times, and minimizing complications in clinical settings. Continued research and development in this field are anticipated to lead to even more sophisticated chitosan-based formulations for tissue repair and wound management. The integration of chitosan with emergent technologies emphasizes its potential as a cornerstone in the future of regenerative medicine and wound care. Initially, this review provides an outline of sources and unique properties of chitosan, followed by recent signs of progress in chitosan-based formulations for tissue engineering and wound healing, underscoring their potential and innovative strategies.

Recent advancements in natural polymers-based self-healing nano-materials for wound dressing

The field of wound healing has witnessed remarkable progress in recent years, driven by the pursuit of advanced wound dressings. Traditional dressing materials have limitations like poor biocompatibility, nonbiodegradability, inadequate moisture management, poor breathability, lack of inherent therapeutic properties, and environmental impacts. There is a compelling demand for innovative solutions to transcend the constraints of conventional dressing materials for optimal wound care. In this extensive review, the therapeutic potential of natural polymers as the foundation for the development of self-healing nano-materials, specifically for wound dressing applications, has been elucidated. Natural polymers offer a multitude of advantages, possessing exceptional biocompatibility, biodegradability, and bioactivity. The intricate engineering strategies employed to fabricate these polymers into nanostructures, thereby imparting enhanced mechanical robustness, flexibility, critical for efficacious wound management has been expounded. By harnessing the inherent properties of natural polymers, including chitosan, alginate, collagen, hyaluronic acid, and so on, and integrating the concept of self-healing materials, a comprehensive overview of the cutting-edge research in this emerging field is presented in the review. Furthermore, the inherent self-healing attributes of these materials, wherein they exhibit innate capabilities to autonomously rectify any damage or disruption upon exposure to moisture or body fluids, reducing frequent dressing replacements have also been explored. This review consolidates the existing knowledge landscape, accentuating the benefits and challenges associated with these pioneering materials while concurrently paving the way for future investigations and translational applications in the realm of wound healing.

Recent Applications of Chitosan and Its Derivatives in Antibacterial, Anticancer, Wound Healing, and Tissue Engineering Fields

Chitosan, a versatile biopolymer derived from chitin, has garnered significant attention in various biomedical applications due to its unique properties, such as biocompatibility, biodegradability, and mucoadhesiveness. This review provides an overview of the diverse applications of chitosan and its derivatives in the antibacterial, anticancer, wound healing, and tissue engineering fields. In antibacterial applications, chitosan exhibits potent antimicrobial properties by disrupting microbial membranes and DNA, making it a promising natural preservative and agent against bacterial infections. Its role in cancer therapy involves the development of chitosan-based nanocarriers for targeted drug delivery, enhancing therapeutic efficacy while minimising side effects. Chitosan also plays a crucial role in wound healing by promoting cell proliferation, angiogenesis, and regulating inflammatory responses. Additionally, chitosan serves as a multifunctional scaffold in tissue engineering, facilitating the regeneration of diverse tissues such as cartilage, bone, and neural tissue by promoting cell adhesion and proliferation. The extensive range of applications for chitosan in pharmaceutical and biomedical sciences is not only highlighted by the comprehensive scope of this review, but it also establishes it as a fundamental component for forthcoming research in biomedicine.

Fabrication of bioinspired keratin/sodium alginate based biopolymeric mat loaded with herbal drug and green synthesized zinc oxide nanoparticles as a dual drug antimicrobial wound dressing

Dual drug antibacterial wound dressings with biological materials possess crucial wound healing characteristics including biocompatibility, non-toxicity, degradability, mechanical strength and antibacterial properties. The study focusses on fabricating keratin (K)‑sodium alginate (A) based wound dressings by loading green synthesized zinc oxide nanoparticles (ZnO NPs) using C. roseus (leaf extract) and M. recutita (Chamomile flower part) herbal drug (CH) as a bioactive dual antibacterial wound dressing for the first time. The optimized ZnO NPs and CH exhibits strong physiochemical and electrostatic interactions (FT-IR, XRD and SEM) on the fabricated K-A-CH-ZnO biopolymeric mats. Moreover, the tiny porous network of the biopolymeric mat enhances thermal stability, hydrophilicity, mechanical strength and explores the water vapor transmission (2538.07 g/m2/day) and oxygen permeability (7.38 ± 0.31 g/m2) to maintain moist environment and cell-material interactions. During enzymatic degradation studies, ZnO NPs and CH of biopolymeric mat not only retains structural integrity but also increases the characteristic of swelling with sustained drug release (57 %) in 144 h which accelerates wound healing process. Also, K-A-CH-ZnO mat exhibited excellent antibacterial effects against B. subtilis and E. coli. Furthermore, NIH 3T3 fibroblast cell behavior using MTT assay and in vivo evaluations of biopolymeric mat depicted enhanced biocompatibility with increased collagen deposition at the wound site as a prominent dual drug medicated antimicrobial wound dressing.

Tissue adhesives based on chitosan for skin wound healing: Where do we stand in this era? A review

Chitosan has been commonly used as an adhesive dressing material due to its excellent biocompatibility, degradability, and renewability. Tissue adhesives are outstanding among wound dressings because they can close the wound, absorb excess tissue exudate from the wound site, provide a moist environment, and act as a carrier for loading various bioactive molecules. They have been widely used in both preclinical and clinical treatment of skin wounds. This review summarizes recent research progresses in the application of chitosan and its derivatives for tissue adhesives. We also introduce their biomedical effects on wound adhesion, contamination isolation, antibacterial, immune regulation, and wound healing, and the strategies to achieve these functions when used as wound dressings. Finally, challenges and future perspectives of chitosan-based tissue adhesives are discussed for wound healing.

Biological activities and wound healing potential of a water-soluble polysaccharide isolated from Glycyrrhiza glabra in Wistar rat

Abstract The present study aimed to evaluate the in vitro antibacterial and antioxidant activities and the in vivo wound healing performance of a polysaccharide isolated from Glycyrrhiza glabra named PSG. It was structurally characterized by Fourier transformed infrared (FT-IR) spectroscopy, which confirmed the presence of different polysaccharides functional bands. The antioxidant capacity of PSG was determined in vitro and evaluated in vivo through the examination of wound healing capacity. Thirty two rats were randomly divided into four groups: group I was treated with physiological serum (negative control); group II was treated with “CYTOL CENTELLA®”; group III was treated with glycerol and group IV was treated with polysaccharide. The response to treatments was assessed by macroscopic, histologic, and biochemical parameters. Data revealed that our sample exhibited potential antioxidant activities and accelerated significantly the wound healing process, after ten days of treatment, proved by the higher wound appearance scores and a higher content of collagen confirmed by histological examination, when compared with control and “CYTOL CENTELLA®”. Overall, these findings proved that this polysaccharide isolated from Glycyrrhiza glabra could be considered as a natural bioactive polymer for therapeutic process in wound healing applications.

Sustainable functionalized chitosan based nano-composites for wound dressings applications: A review

Functionalized chitosan nanocomposites have been studied for wound dressing applications due to their excellent antibacterial and anti-fungal properties. Polysaccharides show excellent antibacterial and drug-release properties and can be utilized for wound healing. In this article, we comprise distinct approaches for chitosan functionalization, such as photosensitizers, dendrimers, graft copolymerization, quaternization, acylation, carboxyalkylation, phosphorylation, sulfation, and thiolation. The current review article has also discussed brief insights on chitosan nanoparticle processing for biomedical applications, including wound dressings. The chitosan nanoparticle preparation technologies have been discussed, focusing on wound dressings owing to their targeted and controlled drug release behavior. The future directions of chitosan research include; a) finding an effective solution for chronic wounds, which are unable to heal completely; b) providing effective wound healing solutions for diabetic wounds and venous leg ulcers; c) to better understanding the wound healing mechanism with such materials which can help provide the optimum solution for wound dressing; d) to provide an improved treatment option for wound healing.

Ulvan/Silver nanoparticle hydrogel films for burn wound dressing

Ulvan is a polysaccharide from green algae that shows good hydrogel film dressing characteristics. Silver nanoparticles (AgNP) can be incorporated into the hydrogel film to improve antibacterial properties and provide a potential burn treatment. In this study, we developed a novel hydrogel film wound dressing composed of ulvan and silver nanoparticles. Two concentrations (0.5 mM and 1 mM) of silver nitrate were used to produce ulvan-silver nanoparticles hydrogel film (UHF-AgNP0.5 and UHF-AgNP1), respectively. The physicochemical characteristics of the hydrogel films were evaluated, including particle size, zeta potential, Fourier transform infrared (FTIR), X-ray diffractometry (XRD), scanning electron microscope and energy-dispersive X-ray (SEM-EDX). Furthermore, the in vitro antimicrobial activity, and second-degree burn wound healing test were evaluated. The UHF-AgNP0.5 showed the highest antimicrobial activity compared to UHF-AgNP1 and UHF film. Meanwhile, an in vivo study using Wistar rats induced second-degree burns showed that UHF-AgNP0.5 significantly accelerated the healing process by regulating the inflammatory process, increasing re-epithelialization, and improving the vascularization process. Ulvan-silver nanoparticle hydrogel films have the ability to accelerate the healing of second-degree burns and are potential candidates for wound dressings.

Chitosan-Based Antibacterial Films for Biomedical and Food Applications

Antibacterial chitosan films, versatile and eco-friendly materials, have garnered significant attention in both the food industry and medicine due to their unique properties, including biodegradability, biocompatibility, and antimicrobial activity. This review delves into the various types of chitosan films and their distinct applications. The categories of films discussed span from pure chitosan films to those enhanced with additives such as metal nanoparticles, metal oxide nanoparticles, graphene, fullerene and its derivatives, and plant extracts. Each type of film is examined in terms of its synthesis methods and unique properties, establishing a clear understanding of its potential utility. In the food industry, these films have shown promise in extending shelf life and maintaining food quality. In the medical field, they have been utilized for wound dressings, drug delivery systems, and as antibacterial coatings for medical devices. The review further suggests that the incorporation of different additives can significantly enhance the antibacterial properties of chitosan films. While the potential of antibacterial chitosan films is vast, the review underscores the need for future research focused on optimizing synthesis methods, understanding structure-property relationships, and rigorous evaluation of safety, biocompatibility, and long-term stability in real-world applications.

Transforming Wound Management: Nanomaterials and Their Clinical Impact

Wound healing is a complex process that can be further complicated in chronic wounds, leading to prolonged healing times, high healthcare costs, and potential patient morbidity. Nanotechnology has shown great promise in developing advanced wound dressings that promote wound healing and prevent infection. The review article presents a comprehensive search strategy that was applied to four databases, namely Scopus, Web of Science, PubMed, and Google Scholar, using specific keywords and inclusion/exclusion criteria to select a representative sample of 164 research articles published between 2001 and 2023. This review article provides an updated overview of the different types of nanomaterials used in wound dressings, including nanofibers, nanocomposites, silver-based nanoparticles, lipid nanoparticles, and polymeric nanoparticles. Several recent studies have shown the potential benefits of using nanomaterials in wound care, including the use of hydrogel/nano silver-based dressings in treating diabetic foot wounds, the use of copper oxide-infused dressings in difficult-to-treat wounds, and the use of chitosan nanofiber mats in burn dressings. Overall, developing nanomaterials in wound care has complemented nanotechnology in drug delivery systems, providing biocompatible and biodegradable nanomaterials that enhance wound healing and provide sustained drug release. Wound dressings are an effective and convenient method of wound care that can prevent wound contamination, support the injured area, control hemorrhaging, and reduce pain and inflammation. This review article provides valuable insights into the potential role of individual nanoformulations used in wound dressings in promoting wound healing and preventing infections, and serves as an excellent resource for clinicians, researchers, and patients seeking improved healing outcomes.

Post grafted gallic acid to chitosan-Ag hybrid nanoparticles via free radical-induced grafting reactions

The present study proposes two unique systems using free radical-induced grafting reactions to combine Ag, chitosan (CS) and gallic acid (GA) into a single particulate nanostructure. GA-grafted-CS (GA-g-CS) was used to reduce Ag⁺ to Ag⁰, and producing Ag-GA-g-CSNPs (hybrid NPs I). Also, GA was grafted into CS-AgNPs, to form GA-g-CS AgNPs (hybrid NPs II). Although there were previous attempts to graft GA into CS, this is first time to graft GA into CS-AgNPs. The study aimed to enhance biocompatibility, antibacterial and antioxidant properties of CS-AgNPs via grafted GA. Grafting GA into CS-AgNPs was confirmed by UV-Vis, DLS, DSC/TGA, XRD, EDX and FTIR. The morphology and size of NPs were studied by TEM and SEM. The decrease of ζ-potential from +50 mV in CS-Ag NPs to +33 and + 29 mV, in the presented 2 nanoforms hybrid NPs I and II, respectively, is an indication for the successful GA graft. Among all samples, hybrid NPs II showed lower toxicity, higher antioxidant and antibacterial activity. The obtained results revealed that grafting GA to CS-AgNPs, as a new method to combine Ag, CS and GA in a uniparticulate structure, is a unique process which may deserve a more future consideration.

Green Synthesis of Titanium Dioxide Nanoparticles Using Ocimum sanctum Leaf Extract: In Vitro Characterization and Its Healing Efficacy in Diabetic Wounds

Diabetes mellitus is one of the most prevalent metabolic disorders characterized by hyperglycemia due to impaired glucose metabolism. Overproduction of free radicals due to chronic hyperglycemia may cause oxidative stress, which delays wound healing in diabetic conditions. For people with diabetes, this impeded wound healing is one of the predominant reasons for mortality and morbidity. The study aimed to develop an Ocimum sanctum leaf extract-mediated green synthesis of titanium dioxide (TiO₂) nanoparticles (NPs) and further incorporate them into 2% chitosan (CS) gel for diabetic wound healing. UV-visible spectrum analysis recorded the sharp peak at 235 and 320 nm, and this was the preliminary sign for the biosynthesis of TiO₂ NPs. The FTIR analysis was used to perform a qualitative validation of the biosynthesized TiO₂ nanoparticles. XRD analysis indicated the crystallinity of TiO₂ NPs in anatase form. Microscopic investigation revealed that TiO₂ NPs were spherical and polygonal in shape, with sizes ranging from 75 to 123 nm. The EDX analysis of green synthesized NPs showed the presence of TiO₂ NPs, demonstrating the peak of titanium ion and oxygen. The hydrodynamic diameter and polydispersity index (PDI) of the TiO₂ NPs were found to be 130.3 nm and 0.237, respectively. The developed TiO₂ NPs containing CS gel exhibited the desired thixotropic properties with pseudoplastic behavior. In vivo wound healing studies and histopathological investigations of healed wounds demonstrated the excellent wound-healing efficacy of TiO₂ NPs containing CS gel in diabetic rats.

The efficacy of a paeoniflorin-sodium alginate-gelatin skin scaffold for the treatment of diabetic wound: An in vivo study in a rat model

OBJECTIVE

To investigate the efficacy of a paeoniflorin-sodium alginate (SA)-gelatin skin scaffold for treating diabetic wound in a rat model.

METHODS

Bioinks were prepared using various percentages of paeoniflorin in the total weight of a solution containing SA and gelatin. Skin scaffolds containing 0%, 1%, 3%, 5%, and 10% paeoniflorin were printed using 3D bioprinting technology, and scaffold microstructure was observed with scanning electron microscopy. Skin scaffolds were then used in rats with diabetic wounds. H&E staining, Masson staining, and immunohistochemical staining for IL-1β and CD31 were performed on days 7 and 14.

RESULTS

All skin scaffolds had a mesh-like structure with uniform pore distribution. Wounds healed well in each group, with the 1% and 3% groups demonstrating the most complete healing. H&E staining showed that skin accessory organs had appeared in each group. On day 7, collagen deposition in the 3% group was higher than in the other groups (P＜0.05), and IL-1β infiltration was lower in the 10% group than in the 3% group (P = 0.002). On day 14, IL-1β infiltration was not significantly different between the 10% and 3% groups (P = 0.078). The CD31 level was higher in the 3% group than in the other groups on days 7 and 14 (P＜0.05).

CONCLUSION

A 3% paeoniflorin-SA-gelatin skin scaffold promoted the healing of diabetic wounds in rats. This scaffold promoted collagen deposition and microvascular regeneration and demonstrated anti-inflammatory properties, suggesting that this scaffold type could be used to treat diabetic wounds.

Application of chitosan nanoparticles in skin wound healing

The rising prevalence of impaired wound healing and the consequential healthcare burdens have gained increased attention over recent years. This has prompted research into the development of novel wound dressings with augmented wound healing functions. Nanoparticle (NP)-based delivery systems have become attractive candidates in constructing such wound dressings due to their various favourable attributes. The non-toxicity, biocompatibility and bioactivity of chitosan (CS)-based NPs make them ideal candidates for wound applications. This review focusses on the application of CS-based NP systems for use in wound treatment. An overview of the wound healing process was presented, followed by discussion on the properties and suitability of CS and its NPs in wound healing. The wound healing mechanisms exerted by CS-based NPs were then critically analysed and discussed in sections, namely haemostasis, infection prevention, inflammatory response, oxidative stress, angiogenesis, collagen deposition, and wound closure time. The results of the studies were thoroughly reviewed, and contradicting findings were identified and discussed. Based on the literature, the gap in research and future prospects in this research area were identified and highlighted. Current evidence shows that CS-based NPs possess superior wound healing effects either used on their own, or as drug delivery vehicles to encapsulate wound healing agents. It is concluded that great opportunities and potentials exist surrounding the use of CSNPs in wound healing.

Nano-silver functionalized polysaccharides as a platform for wound dressings: A review

The healing of defected skin tissue is a complex process, especially for chronic wounds. Poor healing of these wounds may cause extensive suffering and high cost for patients. Traditional wound dressings are typically designed for a single function and they cannot satisfy all requirements for the whole process of wound healing. Therefore, it is necessary to develop new types of wound dressings with multiple functions for wound healing. In particular, adding an antibacterial function has been shown to be of great benefit during tissue repair. Nano‑silver is widely used in wound treatment because of various advantages, such as its wide antibacterial spectrum and lower drug resistance. Therefore, wound dressings loaded with nano‑silver have attracted widespread attention in wound healing. Naturally derived polysaccharides hold great potential as wound dressings, because of their abundant availability, low prices and good biocompatibility. In this review, nano‑silver functionalized polysaccharide-based wound dressings are systematically reviewed, including their preparation methods, antibacterial performances and classification of nano‑silver wound dressings. Moreover, the toxicity of nano‑silver based wound dressings is discussed and the prospective research direction is elaborated. This review aims to provide readers with an overview of the latest developments in silver nanotechnology, and to provide a little guidance for the research of nano‑silver functionalized polysaccharide-based wound dressings.

The Expanded Role of Chitosan in Localized Antimicrobial Therapy

Chitosan is one of the most studied natural origin polymers for biomedical applications. This review focuses on the potential of chitosan in localized antimicrobial therapy to address the challenges of current rising antimicrobial resistance. Due to its mucoadhesiveness, chitosan offers the opportunity to prolong the formulation residence time at mucosal sites; its wound healing properties open possibilities to utilize chitosan as wound dressings with multitargeted activities and more. We provide an unbiased overview of the state-of-the-art chitosan-based delivery systems categorized by the administration site, addressing the site-related challenges and evaluating the representative formulations. Specifically, we offer an in-depth analysis of the current challenges of the chitosan-based novel delivery systems for skin and vaginal infections, including its formulations optimizations and limitations. A brief overview of chitosan's potential in treating ocular, buccal and dental, and nasal infections is included. We close the review with remarks on toxicity issues and remaining challenges and perspectives.

Preparation and characterization of a novel hamada scoparia polysaccharide composite films and evaluation of their effect on cutaneous wound healing in rat

This work was intended to prepare biodegradable and edible films from polysaccharide extracted from Hammada scoparia leaves (named PSP) and reinforced by poly (vinyl alcohol) (PVA). Four films with different ratios of PSP/PVA: P1 (70:30), P2 (50:50), FP3 (30:70) and pure PVA (100 % PVA) were prepared and characterized in terms of structural (FT-IR), physical (Thickness, solubility and swelling index), optical and thermal properties (TGA). The antioxidant activities of different films were determined in vitro and evaluated in vivo through the examination of wound healing capability. Data revealed that the film P1 displayed the highest antioxidant activity in vitro and accelerated significantly the wound healing, after sixteen days of treatment, attested by higher wound appearance scores and a higher content of collagen (765.924 ± 4.44 mg/g of tissue) confirmed by histological examination, when compared with control, CYTOL CENTELLA® and pure PVA-treated groups. Overall, these results demonstrated that PSP/PVA based films exhibited a higher wound healing potential confirmed with the high antioxidant activities in vitro.

Development and Characterization of Ulvan Polysaccharides-Based Hydrogel Films for Potential Wound Dressing Applications

Background

Ulvan is a natural polymer and type of sulfated polysaccharides from green seaweed that could have potential as a candidate for wound dressing material based on the support of its biopolymer characteristics such as antioxidant and antimicrobial activities.

Objective

In this study, we developed and prepared three different hydrogel films to explore the potency of ulvan for wound dressing application.

Methods

Ulvan hydrogel films were prepared by the facile method through ionic crosslinking with boric acid and added glycerol as a plasticizer. The films were evaluated in regard to swelling degree, water vapor transmission (WVTR), Fourier transform infrared (FTIR), powder x-ray diffractometry (P-XRD), scanning electron microscopy (SEM), mechanical properties, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), antimicrobial, and antioxidant activity.

Results

The hydrogel films showed that the different concentration of ulvan in the formula affects the characteristics of the hydrogel film. The higher the concentration of ulvan in UHF, the higher the value of viscosity (201±13.45 to 689±62.23 cps for UHF5 to UHF10), swelling degree (82% to 130% for UHF5 to UHF10 at 1 h), moisture content (24%±1.94% to 18.4%±0.51 for UHF5 to UHF10), and the WVTR were obtained in the range 1856–2590g/m²/24h. Meanwhile, the SEM showed porous hydrogel film. Besides, all hydrogel films can reduce hydroxyl radicals and inhibit gram-positive and negative bacteria (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Streptococcus epidermidis).

Conclusion

The swelling behavior and WVTR of these films are great and could have potential as a wound dressing biomaterial, supported by their antimicrobial and antioxidant properties.

Simvastatin nanoparticles loaded polymeric film as a potential strategy for diabetic wound healing: in vitro and in vivo evaluation

INTRODUCTION

The pleiotropic effects of statins are recently explored for wound healing through angiogenesis and lymph-angiogenesis that could be of great importance in diabetic wounds.

AIM

Aim of the present study is to fabricate nanofilm embedded with simvastatin loaded chitosan nanoparticles (CS-SIM-NPs) has been reported herein to explore the efficacy of SIM in diabetic wound healing.

METHODS

The NPs, prepared via ionic gelation, were 173nm ± 2.645 in size with a zeta potential -0.299 ± 0.009 and PDI 0.051 ± 0.088 with excellent encapsulation efficiency (99.97%). The optimized formulation (CS: TPP, 1:1) that exhibited the highest drug release (91.64%) was incorporated into polymeric nanofilm (HPMC, Sodium alginate, PVA), followed by in vitro characterization. The optimized nanofilm was applied to the wound created on the back of diabetes-induced (with alloxan injection 120 mg/kg) albino rats.

RESULTS

The results showed significant (p < 0.05) improvement in the wound healing process compared to the diabetes-induced non-treated group. The results highlighted the importance of nanofilms loaded with SIM-NPs in diabetic wound healing through angiogenesis promotion at the wound site.

CONCLUSION

Thus, CS-SIM-NPs loaded polymeric nanofilms could be an emerging diabetic wound healing agent in the industry of nanomedicines.

Bioactive Ibuprofen-Loaded PLGA Coatings for Multifunctional Surface Modification of Medical Devices

To modulate the biofunctionality of implantable medical devices commonly used in clinical practice, their surface modification with bioactive polymeric coatings is an attractive and successful emerging strategy. Biodegradable coatings based on poly(lactic acid-co-glycolic acid), PLGA, represent versatile and safe candidates for surface modification of implantable biomaterials and devices, providing additional tunable ability for topical delivery of desired therapeutic agents. In the present study, Ibuprofen-loaded PLGA coatings (PLGA/IBUP) were obtained by using the dip-coating and drop-casting combined protocol. The composite materials demonstrated long-term drug release under biologically simulated dynamic conditions. Reversible swelling phenomena of polymeric coatings occurred in the first two weeks of testing, accompanied by the gradual matrix degradation and slow release of the therapeutic agent. Irreversible degradation of PLGA coatings occurred after one month, due to copolymer's hydrolysis (evidenced by chemical and structural modifications). After 30 days of dynamic testing, the cumulative release of IBUP was ~250 µg/mL. Excellent cytocompatibility was revealed on human-derived macrophages, fibroblasts and keratinocytes. The results herein evidence the promising potential of PLGA/IBUP coatings to be used for surface modification of medical devices, such as metallic implants and wound dressings.

Recent advances in functionalized nanomaterials for the diagnosis and treatment of bacterial infections

The growing problem of resistant infections due to antibiotic misuse is a worldwide concern that poses a grave threat to healthcare systems. Thus, it is necessary to discover new strategies to combat infectious diseases. In this review, we provide a selective overview of recent advances in the use of nanocomposites as alternatives to antibiotics in antimicrobial treatments. Metals and metal oxide nanoparticles (NPs) have been associated with inorganic and organic supports to improve their antibacterial activity and stability as well as other properties. For successful antibiotic treatment, it is critical to achieve a high drug concentration at the infection site. In recent years, the development of stimuli-responsive systems has allowed the vectorization of antibiotics to the site of infection. These nanomaterials can be triggered by various mechanisms (such as changes in pH, light, magnetic fields, and the presence of bacterial enzymes); additionally, they can improve antibacterial efficacy and reduce side effects and microbial resistance. To this end, various types of modified polymers, lipids, and inorganic components (such as metals, silica, and graphene) have been developed. Applications of these nanocomposites in diverse fields ranging from food packaging, environment, and biomedical antimicrobial treatments to diagnosis and theranosis are discussed.

An Updated Review on Silver Nanoparticles in Biomedicine

Silver nanoparticles (AgNPs) represent one of the most explored categories of nanomaterials for new and improved biomaterials and biotechnologies, with impressive use in the pharmaceutical and cosmetic industry, anti-infective therapy and wound care, food and the textile industry. Their extensive and versatile applicability relies on the genuine and easy-tunable properties of nanosilver, including remarkable physicochemical behavior, exceptional antimicrobial efficiency, anti-inflammatory action and antitumor activity. Besides commercially available and clinically safe AgNPs-based products, a substantial number of recent studies assessed the applicability of nanosilver as therapeutic agents in augmented and alternative strategies for cancer therapy, sensing and diagnosis platforms, restorative and regenerative biomaterials. Given the beneficial interactions of AgNPs with living structures and their nontoxic effects on healthy human cells, they represent an accurate candidate for various biomedical products. In the present review, the most important and recent applications of AgNPs in biomedical products and biomedicine are considered.

The application possibility of acellular dermal matrix decorated with nano-silver in the reconstruction of contaminated abdominal wall

Acellular dermal matrix (ADM) is a biomaterial, which commonly used for repair of tissue defects; however, infection is the main factor underlying the failure of treatments involving ADM. To enhance the anti-infection ability of ADM, we constructed a new form of ADM that was decorated with nano-silver ('NS-ADM'). The introduction of nano-silver did not destroy the decellularized structure of ADM, and no significant difference was detected with regards to the maximum tensile force when compared between NS-ADM and ADM (P = 0.351). NS-ADM was not cytotoxic to cell growth when the concentration of nano-silver solution ≤ 25 ppm and exhibited strong antibacterial activity in vitro. Besides, when rats were inoculated with 10⁴ CFU/mL, there were significantly lower bacterial counts in the NS-ADM group than in the ADM group when assessed seven days after surgery (P = 0.047); no significant differences were detected on days 14 and 28. Although there were no significant differences in bacterial counts on days 7, 14, or 21 between the two groups (rats were inoculated with 10⁶ CFU/mL), the number of rats showing reduced bacterial counts or clearing was higher in the NS-ADM group than in the ADM group. Rats that were inoculated with 10⁸ CFU/mL showed repair failure. Overall, NS-ADM is a promising antibacterial biomaterial for repairing contaminated soft-tissue defects, in which antibacterial properties are superior to ADM. The antibacterial activity of NS-ADM was limited for severe infections, and further in vivo studies are needed to evaluate its efficacy and biosafety.