Citric acid cross-linked pomegranate peel extract-loaded pH-responsive β-cyclodextrin/carboxymethyl tapioca starch hydrogel film for diabetic wound healing

Pomegranate peel extract (PPE) hydrogel films filled with citric acid (CA) and β-cyclodextrin-carboxymethyl tapioca starch (CMS) were designed mainly to prevent wound infections and speed up the healing process. FTIR and NMR studies corroborated the carboxymethylation of neat tapioca starch (NS). CMS exhibited superior swelling behavior than NS. The amount of CA and β-CD controlled the physicochemical parameters of developed PPE/CA/β-CD/CMS films. Optimized film (OF) exhibited acceptable swellability, wound fluid absorptivity, water vapor transmission rate, water contact angle, and mechanical properties. Biodegradable, biocompatible, and antibacterial films exhibited pH dependence in the release of ellagic acid for up to 24 h. In mice model, PPE/CA/β-CD/CMS hydrogel film treatment showed promising wound healing effects, including increased collagen deposition, reduced inflammation, activation of the Wingless-related integration site (wnt) pathway leading to cell division, proliferation, and migration to the wound site. The expression of the WNT3A gene did not show any significant differences among all the studied groups. Developed PPE-loaded CA/β-CD/CMS film promoted wound healing by epithelialization, granulation tissue thickness, collagen deposition, and angiogenesis, hence could be recommended as a biodegradable and antibacterial hydrogel platform to improve the cell proliferation during the healing of diabetic wounds.

Wound Healing Performance in a Moist Environment of Crystalline Glucose/Mannose Film as a New Dressing Material Using a Rat Model: Comparing with Medical-Grade Wound Dressing and Alginate

Although medical wound dressings produced using hydrocolloids and alginate were effective in wound healing, adhesion at the wound site and the resulting delayed healing have been a problem. As a new wound dressing material, crystalline wound dressings produced from glucose/mannose were used in this study, which aimed to clarify the properties, adhesion reduction, and wound healing performance of a new wound dressing. Crystalline glucose/mannose films were obtained via alkali treatment using the solution casting method. The structure of the crystalline glucose/mannose films was analogous to the cellulose II polymorph, and the crystallinity decreased with time in hydrated conditions. The crystalline glucose/mannose films had adequate water absorption of 34 × 10-4 g/mm3 for 5 min. These allowed crystalline glucose/mannose films to remove excess wound exudates while maintaining a moist wound healing condition. This in vivo study demonstrated the healing effects of three groups, which were crystalline glucose/mannose group > alginate group > hydrocolloid group. At 1 week, the crystalline glucose/mannose group was also found to be non-adhesive to the portion of wound healing. This was evidenced by the earlier onset of the healing process, which assisted in re-epithelization and promotion of collagen formation and maturation. These results implied that crystalline glucose/mannose films were a promising candidate that could accelerate the wound healing process, compared with medical-grade wound dressing and alginate.

Microwave-Treated Physically Cross-Linked Sodium Alginate and Sodium Carboxymethyl Cellulose Blend Polymer Film for Open Incision Wound Healing in Diabetic Animals-A Novel Perspective for Skin Tissue Regeneration Application

This study aimed at developing the microwave-treated, physically cross-linked polymer blend film, optimizing the microwave treatment time, and testing for physicochemical attributes and wound healing potential in diabetic animals. Microwave-treated and untreated films were prepared by the solution casting method and characterized for various attributes required by a wound healing platform. The optimized formulation was tested for skin regeneration potential in the diabetes-induced open-incision animal model. The results indicated that the optimized polymer film formulation (MB-3) has significantly enhanced physicochemical properties such as high moisture adsorption (154.6 ± 4.23%), decreased the water vapor transmission rate (WVTR) value of (53.0 ± 2.8 g/m²/h) and water vapor permeability (WVP) value (1.74 ± 0.08 g mm/h/m²), delayed erosion (18.69 ± 4.74%), high water uptake, smooth and homogenous surface morphology, higher tensile strength (56.84 ± 1.19 MPa), and increased glass transition temperature and enthalpy (through polymer hydrophilic functional groups depicting efficient cross-linking). The in vivo data on day 16 of post-wounding indicated that the wound healing occurred faster with significantly increased percent re-epithelialization and enhanced collagen deposition with optimized MB-3 film application compared with the untreated group. The study concluded that the microwave-treated polymer blend films have sufficiently enhanced physical properties, making them an effective candidate for ameliorating the diabetic wound healing process and hastening skin tissue regeneration.

Chitosan-based films with cannabis oil as a base material for wound dressing application

This study focuses on obtaining and characterizing novel chitosan-based biomaterials containing cannabis oil to potentially promote wound healing. The primary active substance in cannabis oil is the non-psychoactive cannabidiol, which has many beneficial properties. In this study, three chitosan-based films containing different concentrations of cannabis oil were prepared. As the amount of oil increased, the obtained biomaterials became rougher as tested by atomic force microscopy. Such rough surfaces promote protein adsorption, confirmed by experiments assessing the interaction between human albumin with the obtained materials. Increased oil concentration also improved the films' mechanical parameters, swelling capacity, and hydrophilic properties, which were checked by the wetting angle measurement. On the other hand, higher oil content resulted in decreased water vapour permeability, which is essential in wound dressing. Furthermore, the prepared films were subjected to an acute toxicity test using a Microtox. Significantly, the film's increased cannabis oil content enhanced the antimicrobial effect against A. fischeri for films in direct contact with bacteria. More importantly, cell culture studies revealed that the obtained materials are biocompatible and, therefore, they might be potential candidates for application in wound dressing materials.

Chitosan-Gelatin Films Cross-Linked with Dialdehyde Cellulose Nanocrystals as Potential Materials for Wound Dressings

In this study, thin chitosan-gelatin biofilms cross-linked with dialdehyde cellulose nanocrystals for dressing materials were received. Two types of dialdehyde cellulose nanocrystals from fiber (DNCL) and microcrystalline cellulose (DAMC) were obtained by periodate oxidation. An ATR-FTIR analysis confirmed the selective oxidation of cellulose nanocrystals with the creation of a carbonyl group at 1724 cm⁻¹. A higher degree of cross-linking was obtained in chitosan-gelatin biofilms with DNCL than with DAMC. An increasing amount of added cross-linkers resulted in a decrease in the apparent density value. The chitosan-gelatin biofilms cross-linked with DNCL exhibited a higher value of roughness parameters and antioxidant activity compared with materials cross-linked with DAMC. The cross-linking process improved the oxygen permeability and anti-inflammatory properties of both measurement series. Two samples cross-linked with DNCL achieved an ideal water vapor transition rate for wound dressings, CS-Gel with 10% and 15% addition of DNCL—8.60 and 9.60 mg/cm²/h, respectively. The swelling ability and interaction with human serum albumin (HSA) were improved for biofilms cross-linked with DAMC and DNCL. Significantly, the films cross-linked with DAMC were characterized by lower toxicity. These results confirmed that chitosan-gelatin biofilms cross-linked with DNCL and DAMC had improved properties for possible use in wound dressings.

Freeze-Thaw-Induced Physically Cross-linked Superabsorbent Polyvinyl Alcohol/Soy Protein Isolate Hydrogels for Skin Wound Dressing: In Vitro and In Vivo Characterization

In this work, polyvinyl alcohol (PVA)- and soy protein isolate (SPI)-based scaffolds were prepared by physical cross-linking using the freeze-thaw method. The PVA/SPI ratio was varied to examine the individual effects of the two constituents. The physicochemical properties of the fabricated scaffolds were analyzed through Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, thermogravimetric analysis, and differential scanning calorimetry. The SPI concentration significantly affected the properties of scaffolds, such as the extent of gelation (%), pore size, porosity, degradation, swelling, and surface wettability. The in vitro degradation of fabricated hydrogels was evaluated in phosphate-buffered saline and lysozyme solution for a duration of 14 days. The in vitro compatibility of prepared hydrogels was evaluated by the MTT assay with NIH-3T3 cells (fibroblast). The water vapor transmission rate (WVTR) assays showed that all hydrogels possessed WVTR values in the range of 2000-2500 g m^-2 day^-1, which is generally recommended for ideal wound dressing. Overall, the obtained results reveal that the fabricated scaffolds have excellent biocompatibility, mechanical strength, porosity, stability, and degradation rate and thus carry enormous potential for tissue engineering applications. Furthermore, a full-thickness wound healing study performed in rats supported them as a promising wound dressing material.

Drug Delivery Strategies and Biomedical Significance of Hydrogels: Translational Considerations

Hydrogels are a promising and attractive option as polymeric gel networks, which have immensely fascinated researchers across the globe because of their outstanding characteristics such as elevated swellability, the permeability of oxygen at a high rate, good biocompatibility, easy loading, and drug release. Hydrogels have been extensively used for several purposes in the biomedical sector using versatile polymers of synthetic and natural origin. This review focuses on functional polymeric materials for the fabrication of hydrogels, evaluation of different parameters of biocompatibility and stability, and their application as carriers for drugs delivery, tissue engineering and other therapeutic purposes. The outcome of various studies on the use of hydrogels in different segments and how they have been appropriately altered in numerous ways to attain the desired targeted delivery of therapeutic agents is summarized. Patents and clinical trials conducted on hydrogel-based products, along with scale-up translation, are also mentioned in detail. Finally, the potential of the hydrogel in the biomedical sector is discussed, along with its further possibilities for improvement for the development of sophisticated smart hydrogels with pivotal biomedical functions.

Improvement of Moisture Management Properties of Face Masks Using Electrospun Nanofiber Filter Insert

Face coverings such as a face mask are one of the important preventive measures amidst the COVID-19 pandemic, by limiting exhaled particles and reducing expiratory droplet spread. Adding a filter to face masks may offer extra protection against the virus. Nevertheless, there remains a significant concern where thicker, tightly woven materials of masks may reduce the ability to breathe comfortably, due to inadequate moisture management properties of woven fabric in existing disposable surgical face masks. Therefore, the study on the properties of air permeability, water vapor permeability, and flexural rigidity of a face mask fabric is highly essential. This study is aimed at analyzing the potential application of electrospun nanofibers fabricated from electrospinning technique, as filter inserts in commercial surgical face masks. The function of electrospun nanofiber filter (NF) inserted in commercial surgical face masks was introduced in the study. The results indicated the significant reduction in air permeability and water vapor permeability along with the additional usage of electrospun NF within the surgical face masks, due to the smaller fiber size and interspaces in the filter layer as analyzed from FESEM analysis. The percentage of air permeability value was slightly decreased by 15.9%, from 339.5 to 285.5 mm/s, whereas the value of flexural rigidity of surgical face masks with and without electrospun NF insert is 0.1358 and 0.1207 mg/cm, respectively. Hence, the NF inserts are recommended as the potential core component in a face mask.

Advanced Application of Electrospun Polycaprolactone Fibers for Seed Germination Activity

The increasing intensity of coronavirus (COVID-19) spreading emphasizes the significant development in home food production to reduce the incoming socioeconomic impact from soaring food prices, supply chain fragility, and severe economic crisis. This preliminary study was initiated to demonstrate the possibility of using electrospun fibers as a potential substrate in the application of seed germination activity. The drive of this preliminary study was to integrate the electrospun nanofiber-based material in exploring the current surge in home food production via seed germination in order to introduce cheap source of food without being distracted by the pandemic impact in general. Mung bean (Vigna radiata L. Wilczek) was chosen as it is easy and fast to sprout. Four samples of poly (ε-caprolactone)- (PCL-) based fibers were prepared by means of electrospinning technique, with the optimized flow rate between 0.05 and 0.20 ml/min at a fixed distance of 10 cm needle tip to collector. Mung bean seeds were allowed to germinate on the fabricated electrospun PCL fibers for 96 hours. Our observations include germination percentage, seedling weight, radicle length, and plumule growth. The highest radicle length and plumule length of seedlings were 27.8 mm and 6.7 mm, respectively. There were no inhibitory effects on seed germination and minimal structural fragmentation of smaller diameter electrospun fibers as revealed by FESEM. These results show that the seeds were able to germinate on electrospun PCL fiber substrate, owing to the properties of high surface area and excellent fluid water uptake of PCL fibers.

Formulation and characterisation of alginate hydrocolloid film dressing loaded with gallic acid for potential chronic wound healing

Background: A dramatic growth in the prevalence of chronic wounds due to diabetes has represented serious global health care and economic issues. Hence, there is an imperative need to develop an effective and affordable wound dressing for chronic wounds. Recent research has featured the potential of bioactive compound gallic acid (GA) in the context of wound recovery due to their safety and comparatively low cost. However, there is a scarcity of research that focuses on formulating GA into a stable and functional hydrocolloid film dressing. Thus, this present study aimed to formulate and characterise GA-loaded alginate-based hydrocolloid film dressing which is potentially used as low to medium suppurating chronic wound treatment. Methods: The hydrocolloid composite films were pre-formulated by blending sodium alginate (SA) with different combinations of polymers. The hydrocolloid films were developed using solvent-casting method and the most satisfactory film formulation was further incorporated with various GA concentrations (0.1%, 0.5% and 1%). The drug-loaded films were then characterised for their physicochemical properties to assess their potential use as drug delivery systems for chronic wound treatment. Results: In the pre-formulation studies, sodium alginate-pectin (SA-PC) based hydrocolloid film was found to be the most satisfactory, for being homogenous and retaining smoothness on surface along with satisfactory film flexibility. The SA-PC film was chosen for further loading with GA in 0.1%, 0.5% and 1%. The characterisation studies revealed that all GA-loaded films possess superior wound dressing properties of acidic pH range (3.97-4.04), moderate viscosity (1600 mPa-s-3198 mPa-s), optimal  moisture vapor transmission rate (1195 g/m 2/day, 1237g/m 2/day and 1112 g/m 2/day), slower moisture absorption and film expansion rate and no chemical interaction between the GA and polymers under FTIR analysis. Conclusion: An SA-PC hydrocolloid film incorporated with gallic acid as a potentially applicable wound dressing for low to medium suppurating chronic wounds was successfully developed.

Development of Moringa oleifera Standardized Leaf Extract Nanofibers Impregnated onto Hydrocolloid Film as A Potential Chronic Wound Dressing

This research focuses on the development of a hybrid dressing, i.e. Moringa oleifera (MOL) leave extract nanofibers impregnated onto an alginate-pectin hydrocolloid film for chronic wound healing. The MOL nanofibers impregnated hydrocolloid films were characterised and optimised by physicomechanical properties, moisture transmission, swelling ratio, microscopy analysis, Franz diffusion drug release and cell viability assays. From the preformulation studies, PEO 6 % solution with viscosity above 1.3 Pa·s was found suitable to be electrospun into uniform nanofibers (diameter 322.7±78.02 nm). The moisture transmission rate and swelling ratio studies revealed that the MOL nanofiber-film was useful for the application of light to medium suppurating wounds. The Franz diffusion cell study showed that the electrospun duration could influence the amount of MOL released from the nanofibers-film. Finally, cell viability assays revealed that the MOL nanofibers-films hybrid dressing did not cause cytotoxicity to human dermal fibroblast and human epithelial keratinocytes cell lines. In conclusion, a hybrid MOL nanofibers impregnated hydrocolloid films dressing was successfully formulated and this study has implied that MOL nanofibers-film could be an alternative treatment option for treating chronic wounds.

Development and formulation of Moringa oleifera standardised leaf extract film dressing for wound healing application

ETHNOPHARMACOLOGICAL RELEVANCE

M.oleifera is a medicinal plant traditionally used for skin sores, sore throat and eye infections. Recently, the wound healing property of the leaves of M. oleifera was has been well demonstrated experimentally in both in vivo and in vitro models. However, there is a lack of research which focuses on formulating M.oleifera into a functional wound dressing. In this study, the M.oleifera leaf standardized aqueous extract with highest potency in vitro migration was formulated into a film for wound healing application.

MATERIALS AND METHODS

Firstly, M. oleifera leaf were extracted in various solvents (aqueous, 50%, 70% and 100% ethanolic extracts) and standardized by reference standards using UHPLC technique. The extracts were then tested for cell migration and proliferation using HDF and HEK cell lines. M. oleifera leaf aqueous extract was then incorporated into alginate-pectin (SA-PC) based film dressing. The film dressings were characterized for the physicochemical properties and the bioactives release from the M. oleifera leaf extract loaded film dressing was also investigated using Franz diffusion cells.

RESULTS

All extracts were found to contain vicenin-2, chlorogenic acid, gallic acid, quercetin, kaempferol, rosmarinic acid and rutin. Among all M. oleifera extracts, aqueous standardized leaf extracts showed the highest human dermal fibroblast and human keratinocytes cells proliferation and migration properties. Among the film formulations, SA-PC (3% w/v) composite film dressing containing M. oleifera aqueous leaf extract was found to possess optimal physicochemical properties as wound dressing.

CONCLUSION

A potentially applicable wound dressing formulated as an alginate-pectin film containing aqueous extracts of M. oleifera has been developed. The dressing would be suitable for wounds with moderate exudates.