Curcumin loaded chitosan nanoparticles impregnated into collagen-alginate scaffolds for diabetic wound healing

Collagen fabricated delivery systems for wound healing: A new roadmap

Collagen is a biopolymer found in the animal body. It is one of the most abundant proteins in the extracellular matrix that provides strength to the skin, joints, and bones in the human body. It is an important source of elasticity and strength in the extracellular matrix and contributes to the structural and physiological integrity of tissues. Collagen plays an important role in regulating the wound healing process. It helps in wound healing by attracting fibroblasts and encouraging new collagen formation in the wound bed. Therefore, it can be used as a supplementary aid for wound treatment to accelerate the healing process. A prominent benefit of incorporating collagen in wound dressings is its ability to enhance the healing process for critical wounds. Not only collagen but various collagen-containing systems are being prepared to boost its efficacy in wound healing. Different strategies like nanoscale reductions, biopolymers, and incorporating anti-inflammatory and antimicrobial drugs with collagen have been reported. This review article emphasizes the use of collagen for wound healing and various collagen fabricated delivery systems such as nanofibres, nanoparticles, hydrogels, films, and sponges that aid in the healing of wounds.

Smart biomaterials and their potential applications in tissue engineering

Smart biomaterials have been rapidly advancing ever since the concept of tissue engineering was proposed. Interacting with human cells, smart biomaterials can play a key role in novel tissue morphogenesis. Various aspects of biomaterials utilized in or being sought for the goal of encouraging bone regeneration, skin graft engineering, and nerve conduits are discussed in this review. Beginning with bone, this study summarizes all the available bioceramics and materials along with their properties used singly or in conjunction with each other to create scaffolds for bone tissue engineering. A quick overview of the skin-based nanocomposite biomaterials possessing antibacterial properties for wound healing is outlined along with skin regeneration therapies using infrared radiation, electrospinning, and piezoelectricity, which aid in wound healing. Furthermore, a brief overview of bioengineered artificial skin grafts made of various natural and synthetic polymers has been presented. Finally, by examining the interactions between natural and synthetic-based biomaterials and the biological environment, their strengths and drawbacks for constructing peripheral nerve conduits are highlighted. The description of the preclinical outcome of nerve regeneration in injury healed with various natural-based conduits receives special attention. The organic and synthetic worlds collide at the interface of nanomaterials and biological systems, producing a new scientific field including nanomaterial design for tissue engineering.

Dual-Functional Nanofibrous Patches for Accelerating Wound Healing

Bacterial infections and inflammation are two main factors for delayed wound healing. Coaxial electrospinning nanofibrous patches, by co-loading and sequential co-delivering of anti-bacterial and anti-inflammation agents, are promising wound dressing for accelerating wound healing. Herein, curcumin (Cur) was loaded into the polycaprolactone (PCL) core, and broad-spectrum antibacterial tetracycline hydrochloride (TH) was loaded into gelatin (GEL) shell to prepare PCL-Cur/GEL-TH core-shell nanofiber membranes. The fibers showed a clear co-axial structure and good water absorption capacity, hydrophilicity and mechanical properties. In vitro drug release results showed sequential release of Cur and TH, in which the coaxial mat showed good antioxidant activity by DPPH test and excellent antibacterial activity was demonstrated by a disk diffusion method. The coaxial mats showed superior biocompatibility toward human immortalized keratinocytes. This study indicates a coaxial nanofiber membrane combining anti-bacterial and anti-inflammation agents has great potential as a wound dressing for promoting wound repair.

Novel Curcumin-Encapsulated α-Tocopherol Nanoemulsion System and Its Potential Application for Wound Healing in Diabetic Animals

Objective

This project was aimed at formulating a novel nanoemulsion system and evaluating it for open incision wound healing in diabetic animals.

Methods

The nanoemulsions were characterized for droplet size and surface charge, drug content, antioxidant and antimicrobial profiling, and wound healing potential in diabetic animals. The skin samples excised were also analyzed for histology, mechanical strength, and vibrational and thermal analysis.

Results

The optimized nanoemulsion (CR-NE-II) exhibited droplet size of26.76 ± 0.9 nm with negative surface charge (−10.86 ± 1.06 mV), was homogenously dispersed with drug content of68.05 ± 1.2%, released almost82.95 ± 2.2%of the drug within first 2 h of experiment with synergistic antioxidant (95 ± 2.1%) and synergistic antimicrobial activity against selected bacterial strains in comparison to blank nanoemulsion, and promoted significantly fast percent reepithelization (96.47%). The histological, vibrational, thermal, and strength analysis of selected skin samples depicted a uniform and even distribution of collagen fibers which translated into significant increase in strength of skin samples in comparison to the control group.

Conclusions

The optimized nanoemulsion system significantly downregulated the oxidative stress, enhanced collagen deposition, and precluded bacterial contamination of wound, thus accelerating the skin tissue regeneration process.

Bioactive functional collagen-oxidized pullulan scaffold loaded with polydatin for treating chronic wounds

Prolonged inflammation, elevated matrix metalloproteinases, hypoxia, decreased vascularization, increased oxidative stress, and bacterial infection are typical signs of chronic non-healing diabetic wounds. Any agent that improves one or all factors could offer enhanced opportunities for better healing of diabetic wounds. In this study, a polyphenol (polydatin) incorporated collagen scaffold was prepared using a biocompatible crosslinker, oxidized pullulan (Col-OxP3-Po), to treat diabetic wounds. The scaffolds were characterized using SEM, FTIR, antioxidant activity, in vitro and in vivo wound healing assay, gene expression, and immunohistopathological studies. Polydatin incorporated scaffold exhibited 75 % antioxidant activity, hemostatic and erythrocyte adhesion properties. FTIR results proved the incorporation of polydatin in the Col-OxP3-Po scaffold. They were also non-toxic to the 3 T3 fibroblasts with a viability of 93 % and good cell attachment. In vivo, normal and diabetic wound healing studies showed that the Col-OxP3-Po scaffold treated group healed on days 16 and 21. The histological and immunohistochemistry analyses of the granulation tissues showed improved epithelialization, angiogenesis and enhanced collagen deposition by modulating TGF-β3 and MMP - 9 gene expressions favorable for better healing. Thus, this scaffold could be a newer treatment strategy for chronic non-healing wounds.

Nrf2 Mediated Heme Oxygenase-1 Activation Contributes to Diabetic Wound Healing - an Overview

Diabetic wound healing is a complicated procedure because hyperglycemia changes the various stages of wound healing. In type 2 diabetes mellitus (T2DM), oxidative stress is proven to be a critical factor in causing non-healing wounds and aggravating the inflammatory phase, resulting in the amputation of lower limbs in T2DM patients. This makes scientists figure out how to control oxidative stress and chronic inflammation at the molecular level. Nuclear factor erythroid 2- related factor 2 (Nrf2) releases antioxidant proteins to suppress reactive oxygen species (ROS) activation and inflammation. The current review discusses the role of Nrf2 in improving diabetic wound healing by reducing the production of ROS and thus reducing oxidative stress, as well as inhibiting nuclear factor kappa B (NF-kB) dissociation and nuclear translocation, which prevents the release of inflammatory mediators and increases antioxidant protein levels, thereby improving diabetic wound healing. As a result, the researcher will be able to find a more effective diabetic wound healing therapy.

Current Advances in the Development of Hydrogel-Based Wound Dressings for Diabetic Foot Ulcer Treatment

Diabetic foot ulcers (DFUs) are one of the most prevalent complications associated with diabetes mellitus. DFUs are chronic injuries that often lead to non-traumatic lower extremity amputations, due to persistent infection and other ulcer-related side effects. Moreover, these complications represent a significant economic burden for the healthcare system, as expensive medical interventions are required. In addition to this, the clinical treatments that are currently available have only proven moderately effective, evidencing a great need to develop novel strategies for the improved treatment of DFUs. Hydrogels are three-dimensional systems that can be fabricated from natural and/or synthetic polymers. Due to their unique versatility, tunability, and hydrophilic properties, these materials have been extensively studied for different types of biomedical applications, including drug delivery and tissue engineering applications. Therefore, this review paper addresses the most recent advances in hydrogel wound dressings for effective DFU treatment, providing an overview of current perspectives and challenges in this research field.

Recent Progress in Development of Dressings Used for Diabetic Wounds with Special Emphasis on Scaffolds

Diabetic wound (DW) is a secondary application of uncontrolled diabetes and affects about 42.2% of diabetics. If the disease is left untreated/uncontrolled, then it may further lead to amputation of organs. In recent years, huge research has been done in the area of wound dressing to have a better maintenance of DW. These include gauze, films, foams or, hydrocolloid-based dressings as well as polysaccharide- and polymer-based dressings. In recent years, scaffolds have played major role as biomaterial for wound dressing due to its tissue regeneration properties as well as fluid absorption capacity. These are three-dimensional polymeric structures formed from polymers that help in tissue rejuvenation. These offer a large surface area to volume ratio to allow cell adhesion and exudate absorbing capacity and antibacterial properties. They also offer a better retention as well as sustained release of drugs that are directly impregnated to the scaffolds or the ones that are loaded in nanocarriers that are impregnated onto scaffolds. The present review comprehensively describes the pathogenesis of DW, various dressings that are used so far for DW, the limitation of currently used wound dressings, role of scaffolds in topical delivery of drugs, materials used for scaffold fabrication, and application of various polymer-based scaffolds for treating DW.

Chitosan nanoparticles and their combination with methyl jasmonate for the elicitation of phenolics and flavonoids in plant cell suspension cultures

Productivity enhancement approaches, such as elicitation can overcome the limitations of low metabolite(s) yield in in vitro plant cell culture platforms. Application of biotic/abiotic elicitors triggers molecular responses that lead to a concomitant enhancement in the production of metabolites. Nanoparticles have been tested as alternatives to commonly studied biotic/abiotic elicitors. However, most nanoparticles explored are of metallic origin, which raises concerns about their cytotoxicity, disposal post-elicitation, and may limit downstream applications of metabolites. Here, we report the synthesis and application of biopolymeric methyl jasmonate-loaded chitosan nanoparticles (MJ-CNPs) and empty CNPs (size <100 nm) as nano-elicitors, which were simple to synthesize, cost-effective and safe. Enzymatic and metabolic investigations revealed that MJ-CNPs and empty CNPs improve and prolong phenylalanine ammonia-lyase enzyme activity and production of phenolics and flavonoids. The data provides the first evidence of MJ-CNPs and empty CNPs as nano-elicitors that prolong the production of metabolites in plant cell suspension cultures.

Gelatin-lecithin-F127 gel mediated self-assembly of curcumin vesicles for enhanced wound healing

Curcumin, a principal component of Curcuma longa, has a long history of being used topically for wound healing. However, poor aqueous solubility of curcumin leads to poor topical absorption. Recently, gelatin based gel has been reported to overcome this issue. However, the release of curcumin from gelatin gel in the bioavailable or easily absorbable form is still a challenge. The present study reports the development of a composite gel prepared from gelatin, F127 and lecithin using temperature dependant gelation and loading of curcumin within it. Notably, the composite gel facilitated the release of curcumin entrapped within vesicles of ~400 nm size. Further, the composite gel exhibited increase in the storage modulus or gel strength, stability, pore size and hydrophobicity as compared to only gelatin gel. Finally, wound healing assay in murine model indicated that curcumin delivered through composite gel showed a significantly faster healing as compared to that delivered through organic solvent. This was also validated by histopathological and biochemical analysis showing better epithelization and collagen synthesis in the group dressed with curcumin containing composite gel. In conclusion, composite gel facilitated the release of bioavailable or easily absorbable curcumin which in turn enhanced the wound healing.

Protein by-products: Composition, extraction, and biomedical applications

Significant upsurge in animal by-products such as skin, bones, wool, hides, feathers, and fats has become a global challenge and, if not properly disposed of, can spread contamination and viral diseases. Animal by-products are rich in proteins, which can be used as nutritional, pharmacologically functional ingredients, and biomedical materials. Therefore, recycling these abundant and renewable by-products and extracting high value-added components from them is a sustainable approach to reclaim animal by-products while addressing scarce landfill resources. This article appraises the most recent studies conducted in the last five years on animal-derived proteins' separation and biomedical application. The effort encompasses an introduction about the composition, an overview of the extraction and purification methods, and the broad range of biomedical applications of these ensuing proteins.

How Effective are Nano-Based Dressings in Diabetic Wound Healing? A Comprehensive Review of Literature

Chronic wound caused by diabetes is an important cause of disability and seriously affects the quality of life of patients. Therefore, it is of great clinical significance to develop a wound dressing that can accelerate the healing of diabetic wounds. Nanoparticles have great advantages in promoting diabetic wound healing due to their antibacterial properties, low cytotoxicity, good biocompatibility and drug delivery ability. Adding nanoparticles to the dressing matrix and using nanoparticles to deliver drugs and cytokines to promote wound healing has proven to be effective. This review will focus on the effects of diabetes on wound healing, introduce the properties, preparation methods and action mechanism of nanoparticles in wound healing, and describe the effects and application status of various nanoparticle-loaded dressings in diabetes-related chronic wound healing.

A review of wound dressing materials and its fabrication methods: emphasis on three-dimensional printed dressings

A wound is a trauma caused by some adverse external or blunt forces that can damage the body tissues. Wound healing is a complex process that occurs post-injury which involves the revamping of the structure and function of damaged tissues. Scaffolds are engineered tissue structures manufactured using different materials and methods for facilitating the wound healing process. For external wounds, the antimicrobial property and ability to absorb moisture play an important role in the material selection of the scaffold. Among different methods that exist for designing scaffolds, three-dimensional printing has emerged as a promising technique wherein customised scaffolds can be designed. However, the literature on three-dimensional printed dressings is very much limited compared to conventional ones. Therefore, this review specifically focuses on the methods used to design the scaffolds with special emphasis on different three-dimensional printing techniques. It covers the process of external wound healing, different materials used in the fabrication of scaffolds, and their advantages and drawbacks.

Alginate: Enhancement Strategies for Advanced Applications

Alginate is an excellent biodegradable and renewable material that is already used for a broad range of industrial applications, including advanced fields, such as biomedicine and bioengineering, due to its excellent biodegradable and biocompatible properties. This biopolymer can be produced from brown algae or a microorganism culture. This review presents the principles, chemical structures, gelation properties, chemical interactions, production, sterilization, purification, types, and alginate-based hydrogels developed so far. We present all of the advanced strategies used to remarkably enhance this biopolymer's physicochemical and biological characteristics in various forms, such as injectable gels, fibers, films, hydrogels, and scaffolds. Thus, we present here all of the material engineering enhancement approaches achieved so far in this biopolymer in terms of mechanical reinforcement, thermal and electrical performance, wettability, water sorption and diffusion, antimicrobial activity, in vivo and in vitro biological behavior, including toxicity, cell adhesion, proliferation, and differentiation, immunological response, biodegradation, porosity, and its use as scaffolds for tissue engineering applications. These improvements to overcome the drawbacks of the alginate biopolymer could exponentially increase the significant number of alginate applications that go from the paper industry to the bioprinting of organs.

Potential Wound Healing Effect of Gel Based on Chicha Gum, Chitosan, and Mauritia flexuosa Oil

Wounds are considered a clinically critical issue, and effective treatment will decrease complications, prevent chronic wound formation, and allow rapid healing. The development of products based on naturally occurring materials is an efficient approach to wound healing. Natural polysaccharides can mimic the extracellular matrix and promote cell growth, thus making them attractive for wound healing. In this context, the aim of this work was to produce a gel based on chicha gum, chitosan, and Mauritia flexuosa oil (CGCHO) for wound treatment. TG and DTG analyzed the thermal behavior of the materials, and SEM investigated the surface roughness. The percentages of total phenolic compounds, flavonoids, and antioxidants were determined, presenting a value of 81.811 ± 7.257 µmol gallic acid/g Mauritia flexuosa oil, 57.915 ± 0.305 µmol quercetin/g Mauritia flexuosa oil, and 0.379 mg/mL, respectively. The anti-inflammatory was determined, presenting a value of 10.35 ± 1.46% chicha gum, 16.86 ± 1.00% Mauritia flexuosa oil, 10.17 ± 1.05% CGCHO, and 15.53 ± 0.65% chitosan, respectively. The materials were tested against Gram-negative (Klebsiella pneumoniae) and Gram-positive (Staphylococcus aureus) bacteria and a fungus (Candida albicans). The CGCHO formulation showed better antimicrobial activity against Gram-positive bacteria. In addition, an in vivo wound healing study was also performed. After 21 days of treatment, the epidermal re-epithelialization process was observed. CGCHO showed good thermal stability and roughness that can help in cell growth and promote the tissue healing process. In addition to the good results observed for the antimicrobial, antioxidant, anti-inflammatory activities and providing wound healing, they provided the necessary support for the healing process, thus representing a new approach to the wound healing process.

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.

Biomedical applications of polysaccharide nanoparticles for chronic inflammatory disorders: Focus on rheumatoid arthritis, diabetes and organ fibrosis

Polysaccharides are biopolymers distinguished by their complex secondary structures executing various roles in microorganisms, plants, and animals. They are made up of long monomers of similar type or as a combination of other monomeric chains. Polysaccharides are considered superior as compared to other polymers due to their diversity in charge and size, biodegradability, abundance, bio-compatibility, and less toxicity. These natural polymers are widely used in designing of nanoparticles (NPs) which possess wide applications in therapeutics, diagnostics, delivery and protection of bioactive compounds or drugs. The side chain reactive groups of polysaccharides are advantageous for functionalization with nanoparticle-based conjugates or therapeutic agents such as small molecules, proteins, peptides and nucleic acids. Polysaccharide NPs show excellent pharmacokinetic and drug delivery properties, facilitate improved oral absorption, control the release of drugs, increases in vivo retention capability, targeted delivery, and exert synergistic effects. This review updates the usage of polysaccharides based NPs particularly cellulose, chitosan, hyaluronic acid, alginate, dextran, starch, cyclodextrins, pullulan, and their combinations with promising applications in diabetes, organ fibrosis and arthritis.

Mupirocin-Loaded Chitosan Microspheres Embedded in Piper betle Extract Containing Collagen Scaffold Accelerate Wound Healing Activity

This study reports the formulation of mupirocin-loaded chitosan microspheres embedded in Piper betle extract containing collagen scaffold as combinational drug delivery for improved wound healing. Selection of chitosan type (molecular weight and degree of deacetylation) was carried out based on their antibacterial efficacy. The low molecular weight chitosan was selected owing to the highest antibacterial action against gram-positive as well as gram-negative bacteria. Low molecular weight chitosan-microspheres showed spherical shape with largely smooth surface morphology, 11.81% of mupirocin loading, and its controlled release profile. The XRD, DSC thermograms, and FT-IR spectral analysis revealed the mupirocin loaded in molecularly dispersed or in amorphous form, and having no chemical interactions with the chitosan matrix, respectively. The in vivo study indicates potential effect of the mupirocin, Piper betle, and chitosan in the collagen scaffold in the wound healing efficiency with approximately 90% wound healing observed at the end of 15 days of study for combinational drug-loaded chitosan microspheres-collagen scaffold-treated group. The histopathology examination further revealed tissue lined by stratified squamous epithelium, collagen deposition, fibroblastic proliferation, and absence of inflammation indicating relatively efficient wound healing once treated with combinational drug-loaded chitosan microspheres containing scaffold.

Protein materials as sustainable non- and minimally invasive strategies for biomedical applications

Protein-based materials have found applications in a wide range of biomedical fields because of their biocompatibility, biodegradability and great versatility. Materials of different physical forms including particles, hydrogels, films, fibers and microneedles have been fabricated e.g. as carriers for drug delivery, factors to promote wound healing and as structural support for the generation of new tissue. This review aims at providing an overview of the current scientific knowledge on protein-based materials, and selected preclinical and clinical studies will be reviewed in depth as examples of the latest progress within the field of protein-based materials, specifically focusing on non- and minimally invasive strategies mainly for topical application.

Nanomedicine of Plant Origin for the Treatment of Metabolic Disorders

Metabolic disorders are major clinical challenges of health that are progressing globally. A concurrence of metabolic disorders such as obesity, insulin resistance, atherogenic dyslipidemia, and systematic hypertension leads to metabolic syndrome. Over the past years, the metabolic syndrome leads to a five- and two-fold rise in diabetes mellitus type II and cardiovascular diseases. Natural products specifically plant extracts have insulin-sensitizing, anti-inflammatory, and antioxidant properties and are also considered as an alternative option due to few adverse effects. Nanotechnology is one of the promising strategies, which improves the effectiveness of treatment and limits side effects. This review mainly focuses on plant extract-based nanosystems in the management of the metabolic syndrome. Numerous nano-drug delivery systems, i.e., liposomes, hydrogel nanocomposites, nanoemulsions, micelles, solid lipid, and core–shell nanoparticles, have been designed using plant extracts. It has been found that most of the nano-formulations successfully reduced oxidative stress, insulin resistance, chronic inflammation, and lipid profile in in vitro and in vivo studies as plant extracts interfere with the pathways of metabolic syndrome. Thus, these novel plant-based nanosystems could act as a promising candidate for clinical applications.

Waste-derived biomaterials as building blocks in the biomedical field

Recent developments in the biomedical arena have led to the fabrication of innovative biomaterials by utilizing bioactive molecules obtained from biological wastes released from fruit and beverage processing industries, and fish, meat, and poultry industries. These biological wastes that end up in water bodies as well as in landfills are an affluent source of animal- and plant-derived proteins, bio ceramics and polysaccharides such as collagens, gelatins, chitins, chitosans, eggshell membrane proteins, hydroxyapatites, celluloses, and pectins. These bioactive molecules have been intricately designed into scaffolds and dressing materials by utilizing advanced technologies for drug delivery, tissue engineering, and wound healing relevance. These biomaterials are environment-friendly, biodegradable, and biocompatible, and show excellent tissue regeneration attributes. Additionally, being cost-effective they can reduce the burden on the healthcare system as well as provide a sustainable solution to waste management. In this review, the current trends in the utilization of plant and animal waste-derived biomaterials in various biomedical fields are considered along with a separate section on their applications as xenografts.

Highly Efficient Self-Healing Multifunctional Dressing with Antibacterial Activity for Sutureless Wound Closure and Infected Wound Monitoring

Wound healing represents a major clinical and public healthcare problem that is frequently challenged by infection risks, detrimental consequences on the surrounding tissues, and difficulties to monitor the healing process. Here we report on a novel self-healing, antibacterial, and multifunctional wound dressing for sutureless wound closure and real-time monitoring of the healing parameters. The self-healing elastomer contains cetyltrimethylammonium bromide (CTAB) and has high mechanical toughness (35 MJ m^-3 ), biocompatibility, and outstanding antibacterial activity (bactericidal rate is ≈90% in 12 h), enabling the wound dressing to effectively inhibit bacterial growth and accelerate infected wound healing. In vivo tests based on full-thickness skin incision model shows that the multifunctional wound dressing can help in contracting wound edges and facilitate wound closure and healing, as could be evidenced by notably dense and well-organized collagen deposition. The test provides an evidence that the integrated sensor array within the multifunctional wound dressing can monitor temperature, pH, and glucose level of the wound area in real-time, providing reliable and timely information of the condition of the wound. Ultimately, the reported multifunctional dressing would be of high value in managing the burden associated with wound healing via personalised monitoring and treatment approaches, digital and other people-centred solutions for health care.

Phenytoin-loaded bioactive nanoparticles for the treatment of diabetic pressure ulcers: formulation and in vitro/in vivo evaluation

Drug repurposing offers the chance to explore the full potential of existing drugs while reducing drug development time and costs. For instance, the anticonvulsant drug phenytoin (PHT) has been investigated for its wound healing properties. However, its poor solubility and variability of doses used topically limit its use. Hence, the aim of this study was to improve the properties and wound healing efficacy of PHT for the treatment of diabetic bedsores. PHT was encapsulated, using a modified ionic gelation method, in either positively or negatively charged chitosan-alginate nanoparticles (NPs), which possess previously demonstrated wound healing potential. These NPs were characterized by transmission electron microscopy, differential scanning calorimetry, and Fourier-transform infrared spectroscopy. PHT-loaded NPs were evaluated in vivo for their pressure ulcers' healing potential using diabetic rats. The prepared NPs, especially the positively charged particles, exhibited superior wound healing efficacy compared to PHT suspension, with respect to healing rates, granulation tissue formation, tissue maturation, and collagen content. The positively charged NPs resulted in a 56.54% wound closure at day 7, compared to 37% for PHT suspension. Moreover, skin treated with these NPs showed a mature dermis structure with skin appendages, which were absent in all other groups, in addition to the highest collagen content of 63.65%. In conclusion, the use of a bioactive carrier enhanced the healing properties of PHT and allowed the use of relatively low doses of the drug. Our findings suggest that the prepared NPs offer an effective antibiotic-free delivery system for diabetic wound healing applications.

The Effects of Curcumin Nanoparticles Incorporated into Collagen-Alginate Scaffold on Wound Healing of Skin Tissue in Trauma Patients

Wound healing is a biological process that is mainly crucial for the rehabilitation of injured tissue. The incorporation of curcumin (Cur) into a hydrogel system is used to treat skin wounds in different diseases due to its hydrophobic character. In this study, sodium alginate and collagen, which possess hydrophilic, low toxic, and biocompatible properties, were utilized. Collagen/alginate scaffolds were synthesized, and nanocurcumin was incorporated inside them; their interaction was evaluated by FTIR spectroscopy. Morphological studies investigated structures of the samples studied by FE-SEM. The release profile of curcumin was detected, and the cytotoxic test was determined on the L929 cell line using an MTT assay. Analysis of tissue wound healing was performed by H&E staining. Nanocurcumin was spherical, its average particle size was 45 nm, and the structure of COL/ALG scaffold was visible. The cell viability of samples was recorded in cells after 24 h incubation. Results of in vivo wound healing remarkably showed CUR-COL/ALG scaffold at about 90% (p < 0.001), which is better than that of COL/ALG, 80% (p < 0.001), and the control 73.4% (p < 0.01) groups at 14 days/ The results of the samples’ FTIR indicated that nanocurcumin was well-entrapped into the scaffold, which led to improving the wound-healing process. Our results revealed the potential of nanocurcumin incorporated in COL/ALG scaffolds for the wound healing of skin tissue in trauma patients.

Nanotechnology-based therapeutic applications: in vitro and in vivo clinical studies for diabetic wound healing

Diabetic wounds often indicate chronic complications that are difficult to treat. Unfortunately, existing conventional treatment modalities often cause unpremeditated side effects, given the need to develop alternative therapeutic phenotypes that are safe or have minimal side effects and risks. Nanotechnology-based platforms, including nanotherapeutics, nanoparticles (NPs), nanofibers, nanohydrogels, and nanoscaffolds, have garnered attention for their groundbreaking potential to decipher the biological environment and offer personalized treatment methods for wound healing. These nanotechnology-based platforms can successfully overcome the impediments posed by drug toxicity, existing treatment modalities, and the physiology and complexity of the wound sites. Furthermore, studies have shown that they play an essential role in influencing angiogenesis, collagen production, and extracellular matrix (ECM) synthesis, which are integral in skin repair mechanisms. In this review, we emphasized the importance of various nanotechnology-based platforms for healing diabetic wounds and report on the innovative preclinical and clinical outcomes of different nanotechnology-based platforms. This review also outlined the limitations of existing conventional treatment modalities and summarized the physiology of acute and chronic diabetic wounds.

Chitosan (Poly-(D) glucosamine) based solid lipid nanoparticles of dexibuprofen for topical delivery: Formulation development and characterizations

Chitosan a poly-(D) glucosamine is a polysaccharide made by treating shrimp and other crustacean shells with the alkali sodium hydroxide. It is a hydrophilic polymer that helps to retain the drug inside the solid lipid nanoparticles (SLN’s) and prolongs the release of drug from the carrier system. The purpose of the study was to formulate Chitosan decorated SLN’s for the topical delivery of dexibuprofen by hot pressure homogenization technique. Blank SLN’s, drug loaded SLN’s and Chitosan decorated SLN’s were prepared. Particle size, zeta potential and PDI were determined. FTIR study was conducted to evaluate the compatibility of excipients with the active drug. Surface morphology of SLN’s was determined by field emission scanning electron microscope. Drug content and entrapment efficiency of SLN’s were determined using indirect method. In vitro release and ex vivo permeation study of SLN’s were carried out using Franz diffusion cell. The droplet size fell into the nano range i.e. 132±7 to 424±2 nm which is effective for topical drug delivery system. The PDI of formulations range from 0.21 to 0.42 which depicts the homogeneity of all the SLN’s formulations. Vibrational analysis indicates that there is no interaction between active drug and excipient used in the formulation. The surface morphology revealed the spherical shape of Chitosan decorated SLN’s. The in vitro release of formulations showed 79.91±1.07 to 89.94±1.8 % drug release. The drug permeation study showed high permeation of drug into the skin. The percent drug permeation ranges from 64.15±0.93 to 71.80±0.88% indicating good permeation of drug across the skin. Overall, SLN’s are an effective carrier for topical delivery of dexibuprofen and thus bypasses side effects associated with oral delivery.

Acellular Scaffolds as Innovative Biomaterial Platforms for the Management of Diabetic Wounds

Diabetic wound (DW) is one of the leading complications of patients having a long history of uncontrolled diabetes. Moreover, it also imposes an economic burden on people suffering from wounds to manage the treatment. The major impending factors in the treatment of DW are infection, prolonged inflammation and decreased oxygen levels. Since these non-healing wounds are associated with an extended recovery period, the existing therapies provide treatment for a limited period only. The areas covered in this review are general sequential events of wound healing along with DW's pathophysiology, the origin of DW and success, as well as limitations of existing therapies. This systematic review's significant aspect is to highlight the fabrication, characterization and applications of various acellular scaffolds used to heal DW. In addition to that, cellular scaffolds are also described to a limited extent.

Chitosan-Coated PLGA Nanoparticles Loaded with Peganum harmala Alkaloids with Promising Antibacterial and Wound Healing Activities

Wound healing is a major healthcare concern, and complicated wounds may lead to severe outcomes such as septicemia and amputations. To date, management choices are limited, which warrants the search for new potent wound healing agents. Natural products loaded in poly (lactic-co-glycolic acid) (PLGA) coated with chitosan (CS) constitute a promising antibacterial wound healing formulation. In this work, harmala alkaloid-rich fraction (HARF) loaded into PLGA nanoparticles coated with chitosan (H/CS/PLGA NPs) were designed using the emulsion-solvent evaporation method. Optimization of the formulation variables (HARF: PLGA and CS: PLGA weight ratios, sonication time) was performed using the 33 Box-Behnken design (BBD). The optimal NPs were characterized using transmission electron microscopy (TEM) and Attenuated Total Reflection Fourier-Transformed Infrared Spectroscopy (ATR-FTIR). The prepared NPs had an average particle size of 202.27 ± 2.44 nm, a PDI of 0.23 ± 0.01, a zeta potential of 9.22 ± 0.94 mV, and an entrapment efficiency of 86.77 ± 4.18%. In vitro drug release experiments showed a biphasic pattern where an initial burst of 82.50 ± 0.20% took place in the first 2 h, which increased to 87.50 ± 0.50% over 72 h. The designed optimal H/CS/PLGA NPs exerted high antibacterial activity against Staphylococcus aureus and Escherichia coli (MIC of 0.125 and 0.06 mg/mL, respectively) compared to unloaded HARF (MIC of 0.50 mg/mL). The prepared nanoparticles were found to be biocompatible when tested on human skin fibroblasts. Moreover, the wound closure percentage after 24 h of applying H/CS/PLGA NPs was found to be 94.4 ± 8.0%, compared to free HARF and blank NPs (68.20 ± 5.10 and 50.50 ± 9.40%, respectively). In conclusion, the three components of the developed nanoformulation (PLGA, chitosan, and HARF) have synergistic antibacterial and wound healing properties for the management of infected wounds.

Perspective on the application of medicinal plants and natural products in wound healing: A mechanistic review

Wound is defined as any injury to the body such as damage to the epidermis of the skin and disturbance to its normal anatomy and function. Since ancient times, the importance of wound healing has been recognized, and many efforts have been made to develop novel wound dressings made of the best material for rapid and effective wound healing. Medicinal plants play a great role in the wound healing process. In recent decades, many studies have focused on the development of novel wound dressings that incorporate medicinal plant extracts or their purified active compounds, which are potential alternatives to conventional wound dressings. Several studies have also investigated the mechanism of action of various herbal medicines in wound healing process. This paper attempts to highlight and review the mechanistic perspective of wound healing mediated by plant-based natural products. The findings showed that herbal medicines act through multiple mechanisms and are involved in various stages of wound healing. Some herbal medicines increase the expression of vascular endothelial growth factor (VEGF) and transforming growth factor-β (TGF-β) which play important role in stimulation of re-epithelialization, angiogenesis, formation of granulation tissue, and collagen fiber deposition. Some other wound dressing containing herbal medicines act as inhibitor of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and inducible nitric oxide synthase (iNOS) protein expression thereby inducing antioxidant and anti-inflammatory properties in various phases of the wound healing process. Besides the growing public interest in traditional and alternative medicine, the use of herbal medicine and natural products for wound healing has many advantages over conventional medicines, including greater effectiveness due to diverse mechanisms of action, antibacterial activity, and safety in long-term wound dressing usage.

Analysis of Safety and Effectiveness of Sodium Alginate/Poly(γ-glutamic acid) Microspheres for Rapid Hemostasis

Most preventable deaths after trauma are related to hemorrhage and occur early after injury. Timely hemostatic treatment is essential to minimize blood loss and improve survival. Among the various treatment methods, the most economical and effective is to use a hemostatic agent. A powdered hemostatic agent can be used for wounds of any shape or depth with high compactness and excellent accumulation effect. Herein, we chose the natural, hydrophilic polymer poly(γ-glutamic acid) (γ-PGA) to form composite hemostatic microspheres with sodium alginate (SA), which show good biocompatibility, water absorptivity, and viscosity. The morphology and structure of the hemostatic microspheres were determined using Fourier transform infrared spectroscopy and scanning electron microscopy. The overall safety, hemolysis, pyrogenic, and intradermal irritation tests were examined. The relationship between hemostatic pressure and hemostatic time during microsphere use was also measured. The hemostatic effect was analyzed with a liver, spleen, and femoral artery bleeding model. The composite microspheres were well tolerated in vivo and exhibited better hemostatic effects in animal experiments than a microporous polysaccharide powder compound. Research results showed that SA/γ-PGA microspheres are materials with good hemostatic effect, high safety, and great potential in clinical applications.

Advances in Nanoparticle Delivery System for Erectile Dysfunction: An Updated Review

INTRODUCTION

The use of current available treatment for male erectile dysfunction (ED) has some limitations that are related to efficacy and adverse effects. Nanotechnology has been used as a new tool in medicine to improve these limitations and new medications potentially to alleviate and cure ED.

AIM

To review the currently literature on new nano medications for ED based on scientific and clinical studies, efficacy, safety, mechanisms of action, and to identify gaps for future research.

METHODS

A comprehensive literature review was conducted via Google Scholar, Science Direct, and PubMed on English publications using different keywords such as "erectile dysfunction", "emerging treatments", "nanotechnology", and "herbal medicine". The retrieved papers were organized into groups according to the sections covered in this review paper.

MAIN OUTCOMES MEASURES

We reviewed novel ED treatments such as nanotechnological phosphodiesterase inhibitors, papaverine hydrochloride, sialorphin, adipose tissue-derived stem cells, sonic hedgehog, and herbal medicine.

RESULTS

Numerous preclinical studies have addressed novel phosphodiesterase 5 inhibitors nanoparticle, and their recent delivery systems. Nitric oxide, sialorphin, sonic hedgehog, and herbal medicine loaded nanoparticles and nano adipose tissue-derived stem cells as a potential new treatment for ED. In addition, papaverine-containing nanoparticles have been reported. A limited number of randomized clinical studies have determined the mechanism of these treatments.

CONCLUSION

A literature review on the application of nanotechnology in ED therapy was successfully conducted. New nano medications are promising to treat ED. However, further studies are warranted to further assess their efficacy and safety. Masuku NP, Unuofin JO, Lebelo SL. Advances in Nanoparticle Delivery System for Erectile Dysfunction: An Updated Review. Sex Med 2021;XX:XXXXXX.

Limited Treatment Options for Diabetic Wounds: Barriers to Clinical Translation Despite Therapeutic Success in Murine Models

Significance: Millions of people worldwide suffer from diabetes mellitus and its complications, including chronic diabetic wounds. To date, there are few widely successful clinical therapies specific to diabetic wounds beyond general wound care, despite the vast number of scientific discoveries in the pathogenesis of defective healing in diabetes. Recent Advances: In recent years, murine animal models of diabetes have enabled the investigation of many possible therapeutics for diabetic wound care. These include specific cell types, growth factors, cytokines, peptides, small molecules, plant extracts, microRNAs, extracellular vesicles, novel wound dressings, mechanical interventions, bioengineered materials, and more. Critical Issues: Despite many research discoveries, few have been translated from their success in murine models to clinical use in humans. This massive gap between bench discovery and bedside application begs the simple and critical question: what is still missing? The complexity and multiplicity of the diabetic wound makes it an immensely challenging therapeutic target, and this lopsided progress highlights the need for new methods to overcome the bench-to-bedside barrier. How can laboratory discoveries in animal models be effectively translated to novel clinical therapies for human patients? Future Directions: As research continues to decipher deficient healing in diabetes, new approaches and considerations are required to ensure that these discoveries can become translational, clinically usable therapies. Clinical progress requires the development of new, more accurate models of the human disease state, multifaceted investigations that address multiple critical components in wound repair, and more innovative research strategies that harness both the existing knowledge and the potential of new advances across disciplines.

Nanotherapeutics in the treatment of acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a form of oxygenation failure primarily characterized by rapid inflammation resulting from a direct pulmonary or indirect systemic insult. ARDS has been a major cause of death in the recent COVID-19 outbreak wherein asymptomatic respiratory tract infection progresses to ARDS from pneumonia have emphasized the need for a reliable therapy for the disease. The disease has a high mortality rate of approximately 30-50%. Despite the high mortality rate, a dearth of effective pharmacotherapy exists that demands extensive research in this area. The complex ARDS pathophysiology which remains to be understood completely and the multifactorial etiology of the disease has led to the poor diagnosis, impeded drug-delivery to the deeper pulmonary tissues, and delayed treatment of the ARDS patients. Besides, critically ill patients are unable to tolerate the off-target side effects. The vast domain of nanobiotechnology presents several drug delivery systems offering numerous benefits such as targeted delivery, prolonged drug release, and uniform drug-distribution. The present review presents a brief insight into the ARDS pathophysiology and summarizes conventional pharmacotherapies available to date. Furthermore, the review provides an updated report of major developments in the nanomedicinal approaches for the treatment of ARDS. We also discuss different nano-formulations studied extensively in the ARDS preclinical models along with underlining the advantages as well as challenges that need to be addressed in the future.

Curcumin-laden hyaluronic acid-co-Pullulan-based biomaterials as a potential platform to synergistically enhance the diabetic wound repair

Injectable hydrogel with multifunctional tunable properties comprising biocompatibility, anti-oxidative, anti-bacterial, and/or anti-infection are highly preferred to efficiently promote diabetic wound repair and its development remains a challenge. In this study, we report hyaluronic acid and Pullulan-based injectable hydrogel loaded with curcumin that could potentiate reepithelization, increase angiogenesis, and collagen deposition at wound microenvironment to endorse healing cascade compared to other treatment groups. The physical interaction and self-assembly of hyaluronic acid-Pullulan-grafted-pluronic F127 injectable hydrogel were confirmed using nuclear magnetic resonance (¹H NMR) and Fourier transformed infrared spectroscopy (FT-IR), and cytocompatibility was confirmed by fibroblast viability assay. The CUR-laden hyaluronic acid-Pullulan-g-F127 injectable hydrogel promptly undergoes a sol-gel transition and has proved to potentiate wound healing in a streptozotocin-induced diabetic rat model by promoting 93% of wound closure compared to other groups having 35%, 38%, and 62%. The comparative in vivo study and histological examination was conducted which demonstrated an expeditious recovery rate by significantly reducing the wound healing days i.e. 35 days in a control group, 33 days in the CUR suspension group, 21 days in unloaded injectable, and 13 days was observed in CUR loaded hydrogel group. Furthermore, we suggest that the injectable hydrogel laden with CUR showed a prompt wound healing potential by increasing the cell proliferation and serves as a drug delivery platform for sustained and targeted delivery of hydrophobic moieties.

Fabrication and characterization of Chrysin - A plant polyphenol loaded alginate -chitosan composite for wound healing application

The present study explores the therapeutic efficacy of sodium alginate-chitosan scaffolds loaded with Chrysin (ALG-CS-CHY) for dermal wound management. Scaffolds were prepared by the vacuum freeze-drying method. The physiochemical characterization was done through Fourier Transform Infra-Red Spectroscopy (FTIR), which revealed the interactions between the scaffold's functional groups and the drug. Surface Electron microscopy (SEM) showed a porous architecture varying from 200-400 μm. X-ray Diffraction (XRD) showed an ionic interaction between ALG-CS leading to their excellent compatibility. Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) results suggest increased ALG-CS scaffold's thermal stability. In-vitro biodegradation behavior demonstrated controlled degradation with lysozyme. The swelling ratio was highest in the first hour and decreased slowly with time, and the porosity analysis showed a high degree of porosity. The ALG-CS scaffold showed sustained drug availability and minimized re-application, which contributes to effective healing and treatment. The blood compatibility and whole blood clotting ability of the scaffold significantly improved after incorporating the drug. Calcein AM, Propidium iodide, was used for live and dead cell staining, which confirmed that fabricated ALG-CS-CHY scaffolds are biocompatible and facilitate cell growth and cell proliferation. In-vivo and in-vitro observations show that the experimental group treated using the ALG-CS-CHY reduces the period of re-epithelization, accelerated fibroblast cell migration, and contracted wound significantly (p < 0.001) compared to other groups. ALG-CS-CHY scaffolds also increased collagen deposition, hexosamine synthesis, accelerates angiogenesis, and recruiting immune cells at the site of a wound. These results suggest ALG-CS-CHY scaffold serves as an effective dressing for dermal wound management.

Nanotechnology Approaches in Chronic Wound Healing

Significance: The incidence of chronic wounds is increasing due to our aging population and the augment of people afflicted with diabetes. With the extended knowledge on the biological mechanisms underlying these diseases, there is a novel influx of medical technologies into the conventional wound care market. Recent Advances: Several nanotechnologies have been developed demonstrating unique characteristics that address specific problems related to wound repair mechanisms. In this review, we focus on the most recently developed nanotechnology-based therapeutic agents and evaluate the efficacy of each treatment in in vivo diabetic models of chronic wound healing. Critical Issues: Despite the development of potential biomaterials and nanotechnology-based applications for wound healing, this scientific knowledge is not translated into an increase of commercially available wound healing products containing nanomaterials. Future Directions: Further studies are critical to provide insights into how scientific evidences from nanotechnology-based therapies can be applied in the clinical setting.

Development of a cellulose-based scaffold for sustained delivery of curcumin

Due to the unique properties of cellulose-based materials, they are attractive to be developed in industrial pharmaceutics and biomedical fields. Carboxymethyl-diethyl amino ethyl cellulose scaffold (CM-DEAEC) has been synthesized in the current work as a smart novel derivative of cellulose with a great functionality in drug delivery systems. The scaffolds were well cross-linked with 2% (v/v) epichlorohydrin (ECH), loaded with curcumin (Cur), and then were analyzed by FT-IR, XRD, SEM, and mechanical strength. While developing the ideal delivery platform, curcumin (an important chemotherapeutic agent) was chosen due to its hydrophobicity and poor bioavailability. Thus, we developed a novel scaffold for efficient loading and controlled releasing of curcumin. The swelling ratio of 136%, high curcumin entrapment efficiency (up to 83.7%), sustained in vitro drug release profile, and appropriate degradability in three weeks confirmed significant properties of the CM-DEAEC scaffold. More than 99% antibacterial activity has been observed by the cross-linked curcumin loaded CM-DEAEC scaffolds. Cytotoxicity studies using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and 4',6-diamidino-2-phenylindole (DAPI) staining showed that cross-inked curcumin loaded CM-DEAEC scaffolds did not show any toxicity using L929 cells. All experiments were compared with CMC scaffolds and better characteristics of the novel scaffold for drug delivery have been confirmed.

Optimization and evaluation of ciprofloxacin-loaded collagen/chitosan scaffolds for skin tissue engineering

A novel ciprofloxacin-loaded collagen-chitosan scaffold was developed for the treatment of wound using freeze drying method. The average pore size and porosity of developed scaffold was found to be around 125 µm and 91 ± 0.56%. Moreover, swelling, degradation and mechanical tests profile supported the suitability of scaffold for wound healing process. The scaffold has high degree of hemocompatibility towards the blood and promotes the growth, migration and proliferation of fibroblast. The developed scaffold exhibits antibacterial properties and was found to be efficient against the Gram-negative (E.coli) and Gram-positive (Staphylococcus aureus) bacteria hence can be used for wound healing applications. In vivo study demonstrated that the scaffold not only escalated the tissue regeneration time but also accelerated the wound healing process compared to control. The histological studies revealed better granulation, vascularization, and remodeling of extracellular matrix along with regeneration of epidermal and dermal layer of skin. Overall, the obtained results suggested that the developed skin tissue constructs possess the enormous potential for tissue regeneration and might be a suitable biomaterial for skin tissue engineering applications.

Influence of replacing oregano essential oil by ground oregano leaves on chitosan/alginate-based dressings properties

Biopolymers, as chitosan and alginate, have gained prominence in the biomedical area, mainly for application in wound dressings, as partial replacements for synthetic polymers. The present work aimed to compare the influence of the antimicrobial agent incorporation form on the properties of films prepared by casting. The chitosan/alginate-based films were manufactured containing oregano essential oil (OEO) or ground oregano leaves (OR). The OEO was chosen due to its excellent pharmacological properties, and the substitution by OR can represent an advantageous alternative for minimizing the final cost of the product, by removing the oil extraction step. The films, with different amounts of OEO and OR, were characterized in terms of their morphological, physicochemical, mechanical and antimicrobial properties. The films had properties according to desirable for wound dressing application: water vapor flux less than 35 g m^-2 h^-1, moderate liquid absorption capacity, and similar mechanical properties to human skin. All developed films showed antimicrobial activity against the bacteria Escherichia coli and Staphylococcus aureus. Formulations containing OEO presented the largest inhibition zones, although OR showed high potential for the proposed use. These results suggest that films developed, with both OEO and ground oregano leaves, are promising for use as dressings.

Treatment of diabetic mice by microfluidic system-assisted transplantation of stem cells-derived insulin-producing cells transduced with miRNA

AIMS

Cell-based therapy is a promising approach for the treatment of type-1 diabetes mellitus. Identifying stem cells with differentiation potential to Insulin-producing cells (IPCs) and their application is an emerging issue. Different strategies have been used to support cell survival and their specific functions to control hyperglycemia conditions. Novel technologies using appropriate materials/fibers can improve cell transplantation.

MAIN METHODS

In the present study, IPCs were differentiated from adipose-derived stem cells transduced with miR-375 and anti-miR-7. The cells' survival rate was also improved using a microfluidic system before their in vivo transplantation.

KEY FINDINGS

After adopting a stable, functional condition of the IPCs, the cells were used for in vivo grafting to diabetic mice, which resulted in a substantial drop in blood glucose during four weeks of grafting compared to the control group (p < 0.0001). The pattern of blood glucose levels in the mice receiving fiber entrapped IPCs, was similar to that of non-diabetic mice. Blood insulin was elevated in diabetic mice which received a transplant of fiber-entrapped-IPCs carrying miR-375 and anti-miR-7 after five weeks of transplantation compared to the diabetic mice (p < 0.014).

SIGNIFICANCE

For the first time, this study showed that the two-component microfluidic system is useful for supporting the Collagen-Alginate fiber-entrapped IPCs and the miRNA-based cell therapy. Overall, our data show that the IPC encapsulation using a microfluidic system can support the cells in terms of morphology and biological function and their efficiency for controlling the hyperglycemia condition in diabetic mice.

Current Update of Collagen Nanomaterials-Fabrication, Characterisation and Its Applications: A Review

Tissue engineering technology is a promising alternative approach for improvement in health management. Biomaterials play a major role, acting as a provisional bioscaffold for tissue repair and regeneration. Collagen a widely studied natural component largely present in the extracellular matrix (ECM) of the human body. It provides mechanical stability with suitable elasticity and strength to various tissues, including skin, bone, tendon, cornea and others. Even though exogenous collagen is commonly used in bioscaffolds, largely in the medical and pharmaceutical fields, nano collagen is a relatively new material involved in nanotechnology with a plethora of unexplored potential. Nano collagen is a form of collagen reduced to a nanoparticulate size, which has its advantages over the common three-dimensional (3D) collagen design, primarily due to its nano-size contributing to a higher surface area-to-volume ratio, aiding in withstanding large loads with minimal tension. It can be produced through different approaches including the electrospinning technique to produce nano collagen fibres resembling natural ECM. Nano collagen can be applied in various medical fields involving bioscaffold insertion or fillers for wound healing improvement; skin, bone, vascular grafting, nerve tissue and articular cartilage regeneration as well as aiding in drug delivery and incorporation for cosmetic purposes.

Design and evaluation of ciprofloxacin loaded collagen chitosan oxygenating scaffold for skin tissue engineering

Hypoxia and sepsis are key concerns towards modern regenerative medicine. Oxygen generating biomaterials having antibacterial property aims to answer these concerns. Hypoxia promotes reactive oxygen species at the implant site that delays wound healing. Sepsis in wound also contributes to delay in wound healing. Therefore, scaffold with antibacterial property and oxygen-producing capacities have shown ability to promote wound healing. In the present study oxygen releasing, ciprofloxacin loaded collagen chitosan scaffold was fabricated for sustained oxygen delivery. Calcium peroxide (CPO) acted as a chemical oxygen source. Oxygen release pattern exhibited a sustained release of oxygen with uniform deposition of CPO on the scaffold. The drug release study shows a prolonged, continuous, and sustained release of ciprofloxacin. Cell culture studies depict that scaffold has suitable cell attachment and migration properties for fibroblasts. In vivo studies performed in the skin flip model visually shows better wound healing and less necrosis. Histological studies show the maintenance of tissue architecture and the deposition of collagen. The results demonstrate that the proposed CPO coated ciprofloxacin loaded collagen-chitosan scaffold can be a promising candidate for skin tissue engineering.

Asiaticoside and polylysine-releasing collagen complex for effectively reducing initial inflammatory response using inflamed induced in vitro model

Inflammation is a significant clinical problem that can arise from full-thickness wounds or burn injuries or microbial disease. Although topical wound healing substances could promote rapid wound healing by preventing or reducing the consequences of inflammation, there still remains a need for the development of novel substances that can effectively reduce infection and inflammation in initial wound healing phase. In this study, collagen was combined with asiaticoside (AS) and ε-poly-l-lysine (εPLL). This complex was then applied to in vitro models of infection and inflammation. Collagen-AS coatings inhibited the initial inflammatory response to LPS through a sustained release of AS, and a bilayer coating-εPLL showed a notable antimicrobial effect using microbial infection test. In this study, we determined whether asiaticoside and εPLL have anti-inflammatory and antibacterial effects through different mechanisms. Collectively, the collagen-AS/εPLL complex indicated great therapeutic potentials for accelerate wound healing and the complex may be considered as a artificial scaffold substitute product to full-thickness wound healing.

Influences of Molecular Weights on Physicochemical and Biological Properties of Collagen-Alginate Scaffolds

For tissue engineering applications, biodegradable scaffolds containing high molecular weights (MW) of collagen and sodium alginate have been developed and characterized. However, the properties of low MW collagen-based scaffolds have not been studied in previous research. This work examined the distinctive properties of low MW collagen-based scaffolds with alginate unmodified and modified by subcritical water. Besides, we developed a facile method to cross-link water-soluble scaffolds using glutaraldehyde in an aqueous ethanol solution. The prepared cross-linked scaffolds showed good structural properties with high porosity (~93%) and high cross-linking degree (50–60%). Compared with collagen (6000 Da)-based scaffolds, collagen (25,000 Da)-based scaffolds exhibited higher stability against collagenase degradation and lower weight loss in phosphate buffer pH 7.4. Collagen (25,000 Da)-based scaffolds with modified alginate tended to improve antioxidant capacity compared with scaffolds containing unmodified alginate. Interestingly, in vitro coagulant activity assay demonstrated that collagen (25,000 Da)-based scaffolds with modified alginate (C25-A63 and C25-A21) significantly reduced the clotting time of human plasma compared with scaffolds consisting of unmodified alginate. Although some further investigations need to be done, collagen (25,000 Da)-based scaffolds with modified alginate should be considered as a potential candidate for tissue engineering applications.