Evaluation of wound healing effect of alginate film containing Aloe vera gel and cross-linked with zinc chloride

Chitosan-Aloe Vera Composition Loaded with Zinc Oxide Nanoparticles for Wound Healing: In Vitro and In Vivo Evaluations

Global concerns due to the negative impacts of untreatable wounds, as well as the growing population of these patients, emphasize the critical need for advancements in the wound healing materials and techniques. Nanotechnology offers encouraging avenues for improving wound healing process. In this context, nanoparticles (NPs) and certain natural materials, including chitosan (CS) and aloe vera (AV), have demonstrated the potential to promote healing effects. The objective of this investigation is to assess the effect of novel fabricated nanocomposite gel containing CS, AV, and zinc oxide NPs (ZnO NPs) on the wound healing process. The ZnO NPs were synthesized and characterized by X-ray diffraction and electron microscopy. Then, CS/AV gel with different ratios was prepared and loaded with ZnO NPs. The obtained formulations were characterized in vitro based on an antimicrobial study, and the best formulations were used for the animal study to assess their wound healing effects in 21 days. The ZnO NPs were produced with an average 33 nm particle size and exhibited rod shape morphology. Prepared gels were homogenous with good spreadability, and CS/AV/ZnO NPs formulations showed higher antimicrobial effects against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The wound healing findings showed significant wound area reduction in the CS/AV/ZnO NPs group compared to negative control at day 21. Histopathological assessment revealed the advantageous impact of this formulation across various stages of the wound healing process, including collagen deposition (CS/AV/ZnO NPs (2 : 1), 76.6 ± 3.3 compared to negative control, 46.2 ± 3.7) and epitheliogenesis (CS/AV/ZnO NPs (2 : 1), 3 ± 0.9 compared to negative control, 0.8 ± 0.8). CS/AV gel-loaded ZnO NPs showed significant effectiveness in wound healing and would be suggested as a promising formulation in the wound healing process. Further assessments are warranted to ensure the robustness of our findings.

A novel high water-soluble antibacterial films-based guar gum incorporated with Aloe vera gel and ε-polylysine

The high water-soluble films are commonly used in food coating and food encapsulation. In this study, the effect of Aloe vera gel (AV) and ε-polylysine (ε-PL) on the comprehensive properties of films based on guar gum (GG) were investigated. When GG to AV was 8:2, the GG:AV:ε-PL composite films (water solubility = 68.50%) had an 82.42% higher water solubility than pure guar gum (PGG) films (water solubility = 37.55%). Compared with PGG films, the composite films more transparent, better thermal stability and elongation at break. X-ray diffraction and SEM analysis showed the composite films were amorphous structures and the AV and ε-PL did not change the structure of PGG. FITR analysis confirmed the formation of hydrogen bonds within the composite films. Antibacterial properties showed the composite films had a good antibacterial effect against Escherichia coli and Staphylococcus aureus. Therefore, the composite films can be a new option of high water-soluble antibacterial food packaging materials.

Formulation and In Vivo Evaluation of Biofilm Loaded with Silver Sulfadiazine for Burn Healing

Infected burned skin is a life-threatening condition, which may lead to sepsis. The aims of this work are to formulate a biofilm composed of silver sulfadiazine (SSD), chitosan (CS), and sodium alginate (SA), and to evaluate its wound-healing effectiveness. A full factorial design was used to formulate different matrix formulations. The prepared biofilm was tested for physicochemical, and in vitro release. The optimized formulation is composed of 0.833% of CS and 0.75% of SA. The release of SSD almost reached 100% after 6 h. The mechanical properties of the optimized formula were reasonable. The antibacterial activity for the optimized biofilm was significantly higher than that of blank biofilm, which is composed of CS and SA, p = 1.53922 × 10-12. Moreover, the in vivo study showed a 75% reduction in wound width when using the formulated SSD biofilm compared to standard marketed cream (57%) and the untreated group (0%).

Agar/gelatin hydro-film containing EGF and Aloe vera for effective wound healing

In the current study, we produced a hydro-film dressing for the treatment of chronic wounds. The hydro-film structure was composed of gelatin cross-linked with citric acid, agar and Aloe vera extract (AV); additionally epidermal growth factor (EGF) was loaded to promote wound healing. Due to the excellent hydrogel-forming ability of gelatin, the obtained hydro-film was able to swell 884 ± 36% of its dry weight, which could help controlling wound moisture. To improve gelatin mechanical properties, polymer chains were cross-linked with citric acid and agar, reaching an ultimate tensile strength that was in the highest range of human skin. In addition, it showed a slow degradation profile that resulted in a remaining weight of 28 ± 8% at day 28. Regarding, biological activity, the addition of AV and citric acid provided the ability to reduce human macrophage activation, which could help reverse the permanent inflammatory state of chronic wounds. Moreover, loaded EGF, together with the structural AV of the hydro-film, promoted human keratinocyte and fibroblast migration, respectively. Furthermore, the hydro-films presented excellent fibroblast adhesiveness, so they could be useful as provisional matrices for cell migration. Accordingly, these hydro-films showed suitable physicochemical characteristics and biological activity for chronic wound healing applications.

Multifunctional and biodegradable methacrylated gelatin/Aloe vera nanofibers for endodontic disinfection and immunomodulation

Currently employed approaches and materials used for vital pulp therapies (VPTs) and regenerative endodontic procedures (REPs) lack the efficacy to predictably achieve successful outcomes due to their inability to achieve adequate disinfection and/or lack of desired immune modulatory effects. Natural polymers and medicinal herbs are biocompatible, biodegradable, and present several therapeutic benefits and immune-modulatory properties; thus, standing out as a clinically viable approach capable of establishing a conducive environment devoid of bacteria and inflammation to support continued root development, dentinal bridge formation, and dental pulp tissue regeneration. However, the low stability and poor mechanical properties of the natural compounds have limited their application as potential biomaterials for endodontic procedures. In this study, Aloe vera (AV), as a natural antimicrobial and anti-inflammatory agent, was incorporated into photocrosslinkable Gelatin methacrylate (GelMA) nanofibers with the purpose of developing a highly biocompatible biomaterial capable of eradicating endodontic infection and modulating inflammation. Stable GelMA/AV nanofibers with optimal properties were obtained at the ratio of (70:30) by electrospinning. In addition to the pronounced antibacterial effect against Enterococcus faecalis, the GelMA/AV (70:30) nanofibers also exhibited a sustained antibacterial activity over 14 days and significant biofilm reduction with minimal cytotoxicity, as well as anti-inflammatory properties and immunomodulatory effects favoring healing. Our results indicate that the novel GelMA/AV (70:30) nanofibers hold great potential as a biomaterial strategy for endodontic infection eradication and enhanced healing.

Synergistic Antimicrobial Activity of Magnetite and Vancomycin-Loaded Mesoporous Silica Embedded in Alginate Films

The aim of the present study was to obtain a hydrogel-based film as a carrier for the sustained and controlled release of vancomycin, an antibiotic commonly used in various types of infections. Considering the high-water solubility of vancomycin (>50 mg/mL) and the aqueous medium underlying the exudates, a prolonged release of vancomycin from an MCM-41 carrier was sought. The present work focused on the synthesis of malic acid coated magnetite (Fe3O4/malic) by co-precipitation, synthesis of MCM-41 by a sol-gel method and loading of MCM-41 with vancomycin, and their use in alginate films for wound dressing. The nanoparticles obtained were physically mixed and embedded in the alginate gel. Prior to incorporation, the nanoparticles were characterized by XRD, FT-IR and FT-Raman spectroscopy, TGA-DSC and DLS. The films were prepared by a simple casting method and were further cross-linked and examined for possible heterogeneities by means of FT-IR microscopy and SEM. The degree of swelling and the water vapor transmission rate were determined, considering their potential use as wound dressings. The obtained films show morpho-structural homogeneity, sustained release over 48 h and a strong synergistic enhancement of the antimicrobial activity as a consequence of the hybrid nature of these films. The antimicrobial efficacy was tested against S. aureus, two strains of E. faecalis (including vancomycin-resistant Enterococcus, VRE) and C. albicans. The incorporation of magnetite was also considered as an external triggering component in case the films were used as a magneto-responsive smart dressing to stimulate vancomycin diffusion.

High-Content Aloe vera Based Hydrogels: Physicochemical and Pharmaceutical Properties

The present research focuses on the physicochemical and pharmacotechnical properties of new hydrogels obtained using allantoin, xanthan gum, salicylic acid and different concentrations of Aloe vera (5, 10, 20% w/v in solution; 38, 56, 71 wt% in dry gels). The thermal behavior of Aloe vera composite hydrogels was studied using DSC and TG/DTG analyses. The chemical structure was investigated using different characterization methods (XRD, FTIR and Raman spectroscopies) and the morphology of the hydrogels was studied SEM and AFM microscopy. Pharmacotechnical evaluation on tensile strength and elongation, moisture content, swelling and spreadability was also completed. Physical evaluation confirmed that the appearance of the prepared Aloe vera based hydrogels was homogeneous and the color varied from pale beige to deep opaque beige with increasing Aloe vera concentration. All other evaluation parameters, e.g., pH, viscosity, spreadability and consistency were found to be adequate in all hydrogel formulations. SEM and AFM images show that the structure of the hydrogels condensed into homogeneous polymeric solids with the addition of Aloe vera, in accordance with the decrease in peak intensities observed via XRD analysis. These results suggest interactions between the hydrogel matrix and Aloe vera as observed via FTIR and TG/DTG and DSC analyses. Considering that Aloe vera content higher than 10% (w/v) did not stimulate further interactions, this formulation (FA-10) can be used for further biomedical applications.

Effect of Combination of Hypericum perforatum, Calendula officinalis and Aloe vera Plant Extracts on Incisional Wound Healing

Today, patients and health professionals are turning to innovative approaches due to the lack of success in treating chronic wounds. This study aimed to investigate the effect of a mixture of Hypericum perforatum histopathologically, Calendula officinalis, and Aloe vera plant extracts on incisional wound healing. A total of 14 rats, 7 rats, were used in each group. The groups were divided into experimental and control. While daily wound care was performed with an herbal extract mixture in the experimental group, sterile saline was used for daily wound care in the control group. During the study, wound surface area measurement, macroscopic evaluation, and histopathological examination were performed in both groups. According to research findings, the control group's wound-healing process is shorter. Histopathological analyses revealed that wound healing was completed on day 21.

Recovery of Model Pharmaceutical Compounds from Water and Organic Solutions with Alginate-Based Composite Membranes

In this work, we combined the non-solvent induced phase separation (NIPS) and further cross-linking by cations towards the preparation of nanofiltration membranes based on sodium alginate, a biodegradable, natural polymer. Acetone, ethanol, toluene, and hexane were used as non-solvents, and cations of calcium, silver, and aluminum—for polymer cross-linking, respectively. Results showed the precipitation strength of non-solvent played a noticeable role in the membrane’s performance; for instance, the toluene permeability changed by four orders of magnitude with the decrease of precipitation strength of the non-solvent: acetone (P_toluene = 0.1 kg∙m⁻²∙h⁻¹∙bar⁻¹) < ethanol (3 kg∙m⁻²∙h⁻¹∙bar⁻¹) < hexane (41 kg∙m⁻²∙h⁻¹∙bar⁻¹) < toluene (415 kg∙m⁻²∙h⁻¹∙bar⁻¹). It was shown that simultaneous precipitation and crosslinking in aqueous solutions AlCl₃ or AgNO₃ must be used in the preparation of alginate membranes for the highly selective recovery of pharmaceutical compounds from organic media. These membranes show rejection R = 90–93% of substances with MW = 626 g/mol and ethanol permeability P_EtOH = 1.5–2.5 kg∙m⁻²∙h⁻¹∙bar⁻¹. For the highly selective recovery of pharmaceutical compounds from water, the method of obtaining membranes must be changed. Precipitation in toluene and then crosslinking in aqueous solutions of AlCl₃ or AgNO₃ must be used sequentially instead of simultaneous precipitation and crosslinking in aqueous solutions of the same inorganic salts. The permeability of such membranes varied from 0.44 to 7.8 kg∙m⁻²∙h⁻¹∙bar⁻¹ depending on the crosslinking cation in the alginate. The rejection of model substances with MW 350 and 626 g/mol were on the level of 99%. Alginate membranes can be used to solve separation problems in the pharmaceutical field, for example, to isolate antibiotics from their extractants and remove the same antibiotics from aqueous pharmaceutical waste to prevent their accumulation in the environment and the emergence of resistant genes and bacteria.

A Systematic Review of Oral Nutritional Supplement and Wound Healing

OBJECTIVE

To explore the current literature for effects of oral nutritional supplement on wound healing rates in humans.

METHODS

A systematic review of the literature was performed using the Medline and PubMed database following PRISMA guidelines. The PubMed database was searched using terms relating to oral nutritional supplement and wound healing from 1837 to March 2020. Study inclusion criteria were: (i) design: randomized controlled trials, clinical studies, observational studies, clinical trials; (ii) population: adults; and (iii) intervention: oral nutritional supplement.

RESULTS

The search yielded 2433 studies, 313 of which were clinical trials or clinical studies. After abstract review, 28 studies qualified to be included in the review evaluating the following supplementation categories on wound healing: protein and amino acids (10), mineral, vitamin and antioxidants (9), probiotics (1), and mixed nutrients (8). Arginine and omega-3 supplement were shown to improve wound healing in head and neck cancer patients with surgical wounds by decreasing incidence of postoperative complications and reducing length of hospital stay. Mineral, vitamins, and antioxidants enriched supplements were more beneficial in increasing wound healing than non-enriched protein supplement for diabetic foot and pressure ulcers.

CONCLUSIONS

Supplementation of a variety of nutrients had variable effects on improving wound healing in different types of wounds. However, further research on the impact of nutritional supplements on surgical wound healing is necessary. The impact of multiple nutrient formulations may also need to be further evaluated for efficacy.

Marine Polysaccharides for Wound Dressings Application: An Overview

Wound dressings have become a crucial treatment for wound healing due to their convenience, low cost, and prolonged wound management. As cutting-edge biomaterials, marine polysaccharides are divided from most marine organisms. It possesses various bioactivities, which allowing them to be processed into various forms of wound dressings. Therefore, a comprehensive understanding of the application of marine polysaccharides in wound dressings is particularly important for the studies of wound therapy. In this review, we first introduce the wound healing process and describe the characteristics of modern commonly used dressings. Then, the properties of various marine polysaccharides and their application in wound dressing development are outlined. Finally, strategies for developing and enhancing marine polysaccharide wound dressings are described, and an outlook of these dressings is given. The diverse bioactivities of marine polysaccharides including antibacterial, anti-inflammatory, haemostatic properties, etc., providing excellent wound management and accelerate wound healing. Meanwhile, these biomaterials have higher biocompatibility and biodegradability compared to synthetic ones. On the other hand, marine polysaccharides can be combined with copolymers and active substances to prepare various forms of dressings. Among them, emerging types of dressings such as nanofibers, smart hydrogels and injectable hydrogels are at the research frontier of their development. Therefore, marine polysaccharides are essential materials in wound dressings fabrication and have a promising future.

Current Trends in Advanced Alginate-Based Wound Dressings for Chronic Wounds

Chronic wounds represent a major public health issue, with an extremely high cost worldwide. In healthy individuals, the wound healing process takes place in different stages: inflammation, cell proliferation (fibroblasts and keratinocytes of the dermis), and finally remodeling of the extracellular matrix (equilibrium between metalloproteinases and their inhibitors). In chronic wounds, the chronic inflammation favors exudate persistence and bacterial film has a special importance in the dynamics of chronic inflammation in wounds that do not heal. Recent advances in biopolymer-based materials for wound healing highlight the performance of specific alginate forms. An ideal wound dressing should be adherent to the wound surface and not to the wound bed, it should also be non-antigenic, biocompatible, semi-permeable, biodegradable, elastic but resistant, and cost-effective. It has to give protection against bacterial, infectious, mechanical, and thermal agents, to modulate the level of wound moisture, and to entrap and deliver drugs or other molecules This paper explores the roles of alginates in advanced wound-dressing forms with a particular emphasis on hydrogels, nanofibers networks, 3D-scaffolds or sponges entrapping fibroblasts, keratinocytes, or drugs to be released on the wound-bed. The latest research reports are presented and supported with in vitro and in vivo studies from the current literature.

Current knowledge of immunomodulation strategies for chronic skin wound repair

In orchestrating the wound healing process, the immune system plays a critical role. Hence, controlling the immune system to repair skin defects is an attractive approach. The highly complex immune system includes the coordinated actions of several immune cells, which can produce various inflammatory and antiinflammatory cytokines and affect the healing of skin wounds. This process can be optimized using biomaterials, bioactive molecules, and cell delivery. The present review discusses various immunomodulation strategies for supporting the healing of chronic wounds. In this regard, following the evolution of the immune system and its role in the wound healing mechanism, the interaction between the extracellular mechanism and immune cells for acceleration wound healing will be firstly investigated. Consequently, the immune-based chronic wounds will be briefly examined and the mechanism of progression, and conventional methods of their treatment are evaluated. In the following, various biomaterials-based immunomodulation strategies are introduced to stimulate and control the immune system to treat and regenerate skin defects. Other effective methods of controlling the immune system in wound healing which is the release of bioactive agents (such as antiinflammatory, antigens, and immunomodulators) and stem cell therapy at the site of injury are reviewed.

Scar-Free Healing: Current Concepts and Future Perspectives

Every year, millions of people develop scars due to skin injuries after trauma, surgery, or skin burns. From the beginning of wound healing development, scar hyperplasia, and prolonged healing time in wound healing have been severe problems. Based on the difference between adult and fetal wound healing processes, many promising therapies have been developed to decrease scar formation in skin wounds. Currently, there is no good or reliable therapy to cure or prevent scar formation. This work briefly reviews the engineering methods of scarless wound healing, focusing on regenerative biomaterials and different cytokines, growth factors, and extracellular components in regenerative wound healing to minimize skin damage cell types, and scar formation.