3D-Printed Alginate/Pectin-Based Patches Loaded with Olive Leaf Extracts for Wound Healing Applications: Development, Characterization and In Vitro Evaluation of Biological Properties

Traditional wound dressings may lack suitability for diverse wound types and individual patient requirements. In this context, this study aimed to innovate wound care by developing a 3D-printed patch using alginate and pectin and incorporating Olive Leaf Extract (OLE) as an active ingredient. Different polymer-to-plasticizer ratios were systematically examined to formulate a printable ink with optimal viscosity. The resultant film, enriched with OLE, exhibited a substantial polyphenolic content of 13.15 ± 0.41 mg CAE/g, showcasing significant antioxidant and anti-inflammatory properties. Notably, the film demonstrated potent scavenging abilities against DPPH, ABTS, and NO radicals, with IC50 values of 0.66 ± 0.07, 0.47 ± 0.04, and 2.02 ± 0.14 mg/mL, respectively. In vitro release and diffusion studies were carried out and the release profiles revealed an almost complete release of polyphenols from the patch within 48 h. Additionally, the fabricated film exhibited the capacity to enhance cell motility and accelerate wound healing, evidenced by increased collagen I expression in BJ fibroblast cells. Structural assessments affirmed the ability of the patch to absorb exudates and maintain the optimal moisture balance, while biocompatibility studies underscored its suitability for biomedical applications. These compelling findings endorse the potential application of the developed film in advanced wound care, with the prospect of tailoring patches to individual patient needs.

Carrageenan-Based Compounds as Wound Healing Materials

The following review is focused on carrageenan, a heteroglycan-based substance that is a very significant wound healing biomaterial. Every biomaterial has advantages and weaknesses of its own, but these drawbacks are typically outweighed by combining the material in various ways with other substances. Carrageenans' key benefits include their water solubility, which enables them to keep the wound and periwound damp and absorb the wound exudate. They have low cytotoxicity, antimicrobial and antioxidant qualities, do not stick to the wound bed, and hence do not cause pain when removed from the wounded region. When combined with other materials, they can aid in hemostasis. This review emphasizes the advantages of using carrageenan for wound healing, including the use of several mixes that improve its properties.

Orchestrating the Dermal/Epidermal Tissue Ratio during Wound Healing by Controlling the Moisture Content

A balanced and moist wound environment and surface increases the effect of various growth factors, cytokines, and chemokines, stimulating cell growth and wound healing. Considering this fact, we tested in vitro and in vivo water evaporation rates from the cellulose dressing epicite^hydro when combined with different secondary dressings as well as the resulting wound healing efficacy in a porcine donor site model. The aim of this study was to evaluate how the different rates of water evaporation affected wound healing efficacy. To this end, epicite^hydro primary dressing, in combination with different secondary dressing materials (cotton gauze, JELONET^◊, AQUACEL^® Extra ™, and OPSITE^◊ Flexifix), was placed on 3 × 3 cm-sized dermatome wounds with a depth of 1.2 mm on the flanks of domestic pigs. The healing process was analyzed histologically and quantified by morphometry. High water evaporation rates by using the correct secondary dressing, such as cotton gauze, favored a better re-epithelialization in comparison with the low water evaporation resulting from an occlusive secondary dressing, which favored the formation of a new and intact dermal tissue that nearly fully replaced all the dermis that was removed during wounding. This newly available evidence may be of great benefit to clinical wound management.

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.

Recent Advances in Cellulose-Based Structures as the Wound-Healing Biomaterials: A Clinically Oriented Review

Application of wound-healing/dressing biomaterials is amongst the most promising approaches for wound repair through protection from pathogen invasion/contamination, maintaining moisture, absorbing exudates, modulating inflammation, and facilitating the healing process. A wide range of materials are used to fabricate wound-healing/dressing biomaterials. Active wound-healing/dressings are next-generation alternatives for passive biomaterials, which provide a physical barrier and induce different biological activities, such as antibacterial, antioxidant, and proliferative effects. Cellulose-based biomaterials are particularly promising due to their tunable physical, chemical, mechanical, and biological properties, accessibility, low cost, and biocompatibility. A thorough description and analysis of wound-healing/dressing structures fabricated from cellulose-based biomaterials is discussed in this review. We emphasize and highlight the fabrication methods, applied bioactive molecules, and discuss the obtained results from in vitro and in vivo models of cellulose-based wound-healing biomaterials. This review paper revealed that cellulose-based biomaterials have promising potential as the wound-dressing/healing materials and can be integrated with various bioactive agents. Overall, cellulose-based biomaterials are shown to be effective and sophisticated structures for delivery applications, safe and multi-customizable dressings, or grafts for wound-healing applications.

N-acylhydrazone Derivative-Loaded Cellulose Acetate Films: Thermoanalytical, Spectroscopic, Mechanical and Morphological Characterization

Cellulose acetate (ACT) is one of the most important cellulose derivatives due to its biodegradability and low toxicity, presenting itself as one of the main substitutes for synthetic materials in the development of wound dressing films. The incorporation of a N-acylhydrazonic derivative (JR19), with its promising anti-inflammatory activity, may represent an alternative for the treatment of skin wounds. This work aims to develop and to physicochemically and mechanically characterize ACT films containing JR19. The films were prepared using the ‘casting’ method and further characterized by thermoanalytical and spectroscopic techniques. In addition, mechanical tests and morphological analysis were performed. Thermogravimetry (TG) and differential scanning calorimetry (DSC) analyses showed that the thermal events attributed to excipients and films were similar, indicating the absence of physical incompatibilities between ACT and JR19. Infrared spectroscopy showed that JR19 was incorporated into ACT films. The characteristic band attributed to C≡N (2279 to 2264 cm⁻¹) was observed in the spectra of JR19, in that of the physical mixture of JR19/ACT, and, to a lesser extent, in the spectra of JR19 incorporated into the ACT film, suggesting some interaction between JR19 and ACT. X-ray diffraction (XRD) evidenced the suppression of the crystallinity of JR19 (diffraction peaks at 8.54°, 12.80°, 14.09°, 16.08°, 18.19°, 22.65°, 23.59°, 24.53°, 25.70°, 28.16° and 30.27°2θ) after incorporation into ACT films. The mechanical tests indicated the adequate integrity of the films and their resistance to bending. The morphological characterization showed JR19 crystals along with a homogeneously distributed porous structure throughout the surface of the films with an average diameter of 21.34 µm and 22.65 µm of the films alone and of those incorporating JR19F, respectively. This study was able to characterize the ACT films incorporating JR19, showing their potential to be further developed as wound healing dressings.

Update of Topical Interventions for Healing Diabetic Ulcers-A Systematic Review

There are a variety of dressings for wound healing. For this reason, research can assist in the choice and proper use of the intervention. This current view of the effectiveness of dressing on diabetic foot ulcers (DFUs) in patients with type 2 diabetes mellitus. This study is a systematic review of clinical trials selected in 4 databases: PubMed, Scopus, Web of Science, and Cochrane. Studies without language restriction, published between 2009 and 2020, were included. The search resulted in the identification of 5651 articles, of which 58 met all inclusion criteria. Among these, 2 biomaterials (D-acellular dermal matrix and keratinocyte) and phenytoin were highlighted for achieving healing rates of 100% and 95.82% ± 2.22%, respectively. The literature presents several alternatives with different actions, cure rates, reduction rates, and varied cost benefits. The growth in the use of biomaterials for the treatment of DFU can be seen in this study.

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.

Highly Porous and Superabsorbent Biomaterial Made of Marine-Derived Polysaccharides and Ascorbic Acid as an Optimal Dressing for Exuding Wound Management

There are many modern wound dressings that have promising properties for repairing skin damage. However, due to various types of wounds and the problems they cause, there is still a great demand for new, effective healing strategies. The aim of this study was to create superabsorbent wound dressing made of marine-derived polysaccharides (agarose and chitosan) using the freeze-drying method. The secondary goal was its comprehensive evaluation for potential use as an external superabsorbent bandage for wounds with high exudation. Due to the well-known positive effect of ascorbic acid (vitamin C) on the healing process, biomaterial enriched with vitamin C was prepared and compared to the variant without the addition of ascorbic acid. It was shown that the produced foam-like wound dressing had a very porous structure, which was characterized by hydrophilicity, allowing a large amount of human fluids to be absorbed. According to in vitro tests on human fibroblasts, biomaterial was nontoxic and supportive to cell proliferation. Vitamin C-enriched dressing also had the ability to significantly reduce matrix metalloproteinase-2 production and to promote platelet-derived growth factor-BB synthesis by fibroblasts, which is desired during chronic wound treatment. The material has features of the eco-friendly wound care product since it was made of naturally-derived polysaccharides and was proved to be biodegradable. Importantly, despite degradable character, it was stable in the chronic and infected wound microenvironment, maintaining high integrity after 8-week incubation in the enzymatic solutions containing lysozyme and collagenases. The obtained results clearly showed that developed biomaterial possesses all necessary features of the external dressing for the management of exudate from both acute and chronic non-healing wounds.

PINE NANOCELLULOSE AND BACTERIAL NANOCELLULOSE DRESSINGS ARE SIMILAR IN THE TREATMENT OF SECOND-DEGREE BURN? EXPERIMENTAL STUDY IN RATS

Background: Despite all the advances in medicine and the wide variety of dressings available, the treatment of burn wounds still represents an important medical challenge. The pinus cellulose membrane dressing is a biomaterial with characteristics similar to those of bacterial cellulose, but with lower cost.

Development of NSAID-loaded nano-composite scaffolds for skin tissue engineering applications

Scar free healing together with pain management is one of the major considerations in full thickness wound healing. Extensive wounds take longer to heal without any clinical intervention and, hence, need natural or artificial extracellular matrix support for quick skin regeneration. To address these issues, medicated 3D porous biomimetic scaffolds were developed with a unique combination of biopolymers, that is, chitosan, sodium alginate, and elastin, supplemented with a non-steroidal anti-inflammatory drug (NSAID). Scaffolds were physically characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), swelling ratio analysis, and degradation studies. Findings of the performed analyses proved that these skin substitutes suitable for skin tissue engineering applications attributable to their nano-microporous structures (pore size in range of 0.085-256 μm) allowing cell infiltration and high-water absorption capacity for management of wound exudates. Optimal dose of the loaded ibuprofen was estimated by evaluating effect of variable concentrations of ibuprofen (control, ILM-10, ILM-15, and ILM-20) on adipose tissue-derived mesenchymal stem cells (ASCs) proliferation rate. Out of all experimental groups, ILM-20 constructs were found to accelerate the proliferation rate of seeded ASCs confirming their non-cytotoxic characteristics as well potential to be used for translational scaffold-based therapies.

Design and evaluation of a multifunctional thermosensitive poloxamer-chitosan-hyaluronic acid gel for the treatment of skin burns

The main goal of this study was the design, development and characterization of a poloxamer/chitosan/hyaluronic based vehicle including three biological antioxidant molecules such as vitamins A, D and E aimed at improving the treatment of skin burns. The physical characterization of hydrogel, its mechanical and rheological properties as well as internal structure were investigated. Furthermore, biological characteristics such as ex vivo antimicrobial properties and in vivo wound healing were also accomplished and compared with a commercial reference. Results showed optimal physicochemical properties with biocompatible pH value of 4.6 ± 0.1 and zeta potential dependent on pH. The swelling rate was around 350% with optimal wettability, adhesion and leakage properties, as well as thermosensitive gelation processes. The microbiological assay demonstrated similar antimicrobial activity to that of commercial reference. In vivo tolerance study revealed no skin reactions. Finally, the wound healing efficacy of hydrogel in skin burn model showed dermal appendages and similar epidermis, dermis and stratum corneum to the commercial reference. These findings indicated that our hydrogel loading vitamins could be considered an outstanding candidate for further clinical studies.

Active wound dressings based on bacterial nanocellulose as drug delivery system for octenidine

Although bacterial nanocellulose (BNC) may serve as an ideal wound dressing, it exhibits no antibacterial properties by itself. Therefore, in the present study BNC was functionalized with the antiseptic drug octenidine. Drug loading and release, mechanical characteristics, biocompatibility, and antimicrobial efficacy were investigated. Octenidine release was based on diffusion and swelling according to the Ritger-Peppas equation and characterized by a time dependent biphasic release profile, with a rapid release in the first 8h, followed by a slower release rate up to 96 h. The comparison between lab-scale and up-scale BNC identified thickness, water content, and the surface area to volume ratio as parameters which have an impact on the control of the release characteristics. Compression and tensile strength remained unchanged upon incorporation of octenidine in BNC. In biological assays, drug-loaded BNC demonstrated high biocompatibility in human keratinocytes and antimicrobial activity against Staphylococcus aureus. In a long-term storage test, the octenidine loaded in BNC was found to be stable, releasable, and biologically active over a period of 6 months without changes. In conclusion, octenidine loaded BNC presents a ready-to-use wound dressing for the treatment of infected wounds that can be stored over 6 months without losing its antibacterial activity.

Natural and synthetic polymers for wounds and burns dressing

In the last years, health care professionals faced with an increasing number of patients suffering from wounds and burns difficult to treat and heal. During the wound healing process, the dressing protects the injury and contributes to the recovery of dermal and epidermal tissues. Because their biocompatibility, biodegradability and similarity to macromolecules recognized by the human body, some natural polymers such as polysaccharides (alginates, chitin, chitosan, heparin, chondroitin), proteoglycans and proteins (collagen, gelatin, fibrin, keratin, silk fibroin, eggshell membrane) are extensively used in wounds and burns management. Obtained by electrospinning technique, some synthetic polymers like biomimetic extracellular matrix micro/nanoscale fibers based on polyglycolic acid, polylactic acid, polyacrylic acid, poly-ɛ-caprolactone, polyvinylpyrrolidone, polyvinyl alcohol, polyethylene glycol, exhibit in vivo and in vitro wound healing properties and enhance re-epithelialization. They provide an optimal microenvironment for cell proliferation, migration and differentiation, due to their biocompatibility, biodegradability, peculiar structure and good mechanical properties. Thus, synthetic polymers are used also in regenerative medicine for cartilage, bone, vascular, nerve and ligament repair and restoration. Biocompatible with fibroblasts and keratinocytes, tissue engineered skin is indicated for regeneration and remodeling of human epidermis and wound healing improving the treatment of severe skin defects or partial-thickness burn injuries.