Wound Patch Research Articles

Photocurable Thiol-yne Alginate Hydrogels for Regenerative Medicine Purposes.

Every year millions of people worldwide undergo surgical interventions, with the occurrence of mild or severe post-treatment consequences meaning that rehabilitation plays a key role in modern medicine. Considering the cases of burns and plastic surgery, the pressing need for new materials that can be used for wound patches or body fillers and are able to sustain tissue regeneration and promote cell adhesion and proliferation is clear. The challenges facing next-generation implant materials also include the need for improved structural properties for cellular organization and morphogenic guidance together with optimal mechanical, rheological, and topographical behavior. Herein, we propose for the first time a sodium alginate hydrogel obtained by a thiol-yne reaction, easily synthesized using carbodiimide chemistry in a two-step reaction. The hydrogels were formed in all cases within a few minutes of light irradiation, showing good self-standing properties under solicitation. The mechanical, rheological, topographical, and swelling properties of the gels were also tested and reported. Lastly, no cytotoxicity was detected among the hydrogels. Soluble extracts in culture media allowed cell proliferation, and no differences between samples were detected in terms of metabolic activity and DNA content. These results suggest the potential use of these cytocompatible hydrogels in tissue engineering and regenerative medicine.

Silk-based nano-biocomposite scaffolds for skin organogenesis

Silk produced by silkworms or spiders offers biocompatibility, biodegradability, stability, and biomechanical strength, making it an excellent biomaterial for wound bandages/dressings and skin grafts. Silk scaffolds are also bioactive matrices necessary to restore the healing cascade and barrier properties that induce skin organogenesis in chronic wounds. Silk-based composites are being used to protect wounds from infections. Many studies were conducted via 2D cell culture and in vivo approaches to explain the interaction between skin tissue and silk. In addition to the difficulties that 2D cell culture techniques have in mimicking skin tissue, the physiological differences and immunological incompatibility between in vivo models and human skin tissue make it more complicated to understand the effectiveness of silk scaffolds. This leads to excessive experimental animal usage and false positive or negative results for the clinical stage. Alternatively, organ-like microtissues (organoids, spheroids, among others) produced using stem cells can be a real stakeholder in measuring the success of wound patches due to their 3D structure, cellular diversity, and high yield. However, the fabrication procedure of the microtissues is highly Matrigel-dependent, and it is not the best choice for the studies due to its indeterminate nature, protein concentration, and composition. Silk-based nano-biocomposites can be a good candidate owing to their features above for 3D skin cell culture studies. Here, we evaluated the current applications of silk-based materials in wound healing and their possible applications in 3D tissue engineering for microtissues.

Debonding-On-Demand Polymeric Wound Patches for Minimal Adhesion and Clinical Communication.

Herein, a multifunctional bilayer wound patch is developed by integrating a debonding‐on‐demand polymeric tissue adhesive (DDPTA) with an ionic conducting elastomer (ICE). As a skin adhesive layer, the DDPTA is soft and adherent at skin temperature but hard and non‐tacky when cooled, so it provides unique temperature‐triggered quick adhesion and non‐forced detachment from the skin. During use, the dense surface of the DDPTA prevents blood infiltration and reduces unnecessary blood loss with gentle pressing. Moreover, its hydrophobic matrix helps to repel blood and prevents the formation of clots, thus precluding wound tearing during its removal. This unique feature enables the DDPTA to avoid the severe deficiencies of hydrophilic adhesives, providing a reliable solution for a wide range of secondary wound injuries. The DDPTA is versatile in that it can be covered with ICE to configure a DDPTA@ICE patch for initiating non‐verbal communication systems by the fingers, leading toward sign language recognition and a remote clinical alarm system. This multifunctional wound patch with debonding‐on‐demand can promote a new style of tissue sealant for convenient clinical communication.

Layered dermal reconstitution through epigallocatechin 3-gallate loaded chitosan nanoparticle within enzymatically crosslinked polyvinyl alcohol/collagen fibrous mat.

Biocompatible electrospun fiber comprising bioactive substrates has potential to implant into the wound site as a reliable therapeutic approach in tissue regeneration. Here, electrospun polyvinyl alcohol conjugated tyramine (PVA-Tyr) and collagen (Col) fibrous mat containing chitosan nanoparticle loaded with epigallocatechin 3-gallate (NCs-EGCG) developed and the composite was applied to evaluate in vivo wound healing ability of fabricated wound patch. The synthesized PVA-Tyr and Col were electrospun and crosslinked through peroxidase reaction in presence of vaporized H2O2 as an electron donor which covalently proceeded conjugation of phenolic groups and could develop hybrid fibrous mat in stable structure and uniform shapes. The EGCG as anti-oxidative/inflammatory substrate was encapsulated efficiently in NCs and released in a sustained manner. The hybrid fibers seeded with adipose-derived stem cells presented appropriate biocompatibility from biophysical and biochemical viewpoints and in following wound healing ability in a full-thickness excisional animal model. Fourier transform infrared spectroscopy (FTIR) confirmed all typical absorption characteristics of PVA-Tyr and Col as well as NCs and EGCG. The results showed the perfect hydrophilic/hydrophobic ratio and good mechanical and structural characteristics including shape uniformity and porosity. Interestingly, cellular attachment and proliferation on the PVA-Tyr/Col fibers containing NCs-EGCG were higher than control samples. The histological analysis of hybrid fibrous patch could be suggested the applicability of this structure as suitable skin substitutes to repair injured skin.

IoT-Enabled Integrated Smart Wound Sensor for Multiplexed Monitoring of Inflammatory Biomarkers at the Wound Site

Chronic wounds that stall at the inflammatory phase of healing may create several life-threatening complications such as tissue damage, septicemia, and organ failures. In order to prevent these adverse clinical outcomes and accelerate the wound healing process, it is crucial to monitor the wound status in real-time so that immediate therapeutic interventions can be implemented. In addition, continuous monitoring of the wound status can prevent drug overdose at the wound site, leading to on-demand and personalized drug delivery. Inflammatory mediators, such as Interleukin-6 (IL-6) and Interleukin-10 (IL-10) are promising indicators for the progression of wound healing and predictors of disease severity. Toward this end, this work reports a flexible wound patch for multiplexed monitoring of IL-6 and IL-10 at the wound site in order to provide real-time feedback on the inflammation phase of the wound. An optimized composition of gold nanoparticles integrated multiwalled carbon nanotube was demonstrated to improve sensor performance substantially. The sensor also exhibited excellent repeatable, reversible, and drift characteristics. A miniaturized Internet-of-things (IoT)-enabled potentiostat was also developed and integrated with the flexible sensor to realize a wearable system. This IoT-enabled wearable device provides a smart and cost-effective solution to improving the existing wound care through continuous, real-time, and in-situ monitoring of multiple wound biomarkers.

Self-Bonded Hydrogel Inverse Opal Particles as Sprayed Flexible Patch for Wound Healing.

Wound healing is an important issue for regenerative medicine. Attempts in this area tend to develop functional wound patches to promote the healing. Here, we present self-bonded hydrogel inverse opal particles as sprayed flexible patch for wound healing. Such particles were fabricated by infusing drugs-loaded gelatin (GT) and carrageenan (CG) pregel into inverse opal scaffolds, which were composed of biocompatible hyaluronic acid methacryloyl (HAMA) and gelatin methacryloyl (GelMA) with graphene oxide quantum dots (GO QDs) doping. Due to the photothermal conversion capability of GO QDs and temperature reversible phase-changing performance of GT/CG, the hybrid particles could undergo GT/CG liquid transformation under the near-infrared (NIR) irradiation, which made them adhere to each other and finally form a flexible patch. Following by the phase-change of GT/CG hydrogel, the encapsulated drugs were also controllably released from the inverse opal scaffold. As the inverse opal scaffolds of the hybrid particles were maintained, their drug release induced refractive index changes could be detected as visual structural color shifting, which could be utilized to monitor their delivery processes. Based on these features, we have demonstrated that the self-bonded particles, administered in the form of spray, could be applied for wound tissue healing and drug delivery monitoring. These results indicate that the self-bonded hydrogel particles have potential value as a multifunctional patch for clinical applications.

Fabrication of tragacanthin gum-carboxymethyl chitosan bio-nanocomposite wound dressing with silver-titanium nanoparticles using freeze-drying method

Wound healing is one of the most complex processes that our body has to do, which in some cases is not able to heal itself and needs external stimuli. Controlling wound progression, increasing quality, and accelerating wound healing is the key to solving this global challenge. The use of biological agents in wound dressings is an effective way to modify all aspects of wound healing and has the potential to guide the healing process toward greater recovery. Bio-nanocomposites have always been considered as one of the pre-designed materials and received the attention of bioengineer researchers. In this research, Tragacanthin Gum-Carboxymethyl Chitosan (TG-CMC) bio-nanocomposite wound dressing containing akermanite nanoparticles with different weight percentages of AgO–TiO2 was fabricated using the freeze-drying method. The objectives of this study were to investigate tensile strength, bioactivity, and biodegradability properties. The physical and chemical properties of the wound dress were assessed using X-ray diffraction (XRD), Fourier Transform Infrared Spectroscope (FTIR), and Scanning Electron Microscope (SEM) techniques. Also, the bioactivity and biodegradability of wound dressings were characterized by immersion of samples in Phosphate Buffer Saline (PBS). As a result, the toxicity test of the sample containing 10 wt % AgO–TiO2 oxides has the lower toxicity about 0.943–0.948. The obtained results show that the porosity of the wound dressings is about 65%–79%, which increases by 0.8 with the addition of Ag–TiO2 nanoparticles. As the percentage of porosity increased, it was determined that the tensile strength of the wound patches decreased from 0.35 MPa to 0.15 MPa. The wound dress weight loss results show that the highest weight loss belongs to the sample containing the highest amount of AgO/TiO2. Therefore, the pure sample and the sample with 15 wt% have weight loss about 75% and 81%. The results show that the samples were porous and had interconnected porosities which increased in the presence of akermanite nanoparticles.

In situ wound sprayable double-network hydrogel: Preparation and characterization

In clinical settings the wound-dressing was required easy to use and can match the wound area immediately, at the same time they need to have the properties of hemostats, anti-inflammation and promoting wound healing. To get an ideal wound dressing, we developed a type of gel-like wound adhesive patch from spraying double-network hydrogel, which own the properties of self-antibacterial and can promote wound healing. By spraying, the gel-like wound adhesive patch can match the wound area immediately and form a gel-film in 10 s. Sodium carboxymethyl cellulose as pH sensitive materials accelerated the speed to form the gel-film and enhanced ductility of the wound adhesive patch. In vitro experiments show that, this gel-like wound adhesive patch can promote cell proliferation and reduce cell apoptosis. In vivo studies show that, compared with commercialized wound dressings in clinic using, the spraying gel-like wound adhesive patch from our work has a better effect on wound healing. In conclusion, the spraying gel-like wound patch in our work is easy to use and can form a gel-film match on wound area in a short time, also it has the properties of hemostats, anti-inflammation and promoting wound healing. Its feasibility for mass production shows a good potential for commercial use.

Rapid prototyping of a temperature, humidity, and pressure monitor electronic layer for Pressure Ulcer wound patch

Pressure ulcer is a result of relieving pressure from skin or underlying tissues, causing localized injuries. In this study, a prototype of an electronic monitoring layer that can be placed on top of the wound patch is designed. The electronic layer is comprised of four force-sensitive pressure sensors, and an integrated temperature and humidity sensor to monitor the activities surrounding the wound site. In the simulated wound bed experiments, the results indicated that the utilization of the Bosch BME280 I2C module, when placed on top of a gauze pad, can deliver accurate and real-time monitoring of the temperature and humidity values. Furthermore, the force-sensitive resistors (FSR) installed can be utilized to detect external pressure beyond the set allowable force applied of 32 mmHg or 700g. Therefore, the electronic layer assembled from commercially available sensors can be used to monitor temperature and humidity while being able to detect externally applied pressure in real-time. However, improvements in the size and flexibility of the electronic layer are necessary to reduce the discomfort that patients suffering from pressure ulcers will experience.

Suction Cups-Inspired Adhesive Patch with Tailorable Patterns for Versatile Wound Healing.

Medical patches play an important role in wound healing because of their tissue conformality, drug release capacity, and convenient operation. Great efforts have been devoted to developing new‐generation patches with distinctive features promoting wound healing. Here, inspired by the structure of octopus suction cups and the component of natural tissue, a biocompatible wound patch with selective adhesiveness and individualized design using a combined strategy of template‐replication and mask‐guided lithography is presented. Such patches are based on Ecoflex film with suction‐cup‐mimicking microstructures to adhere to normal skin and with biocompatible gelatin methacryloyl (GelMA) hydrogel to contact wounded areas. An ultraviolet mask with a tailorable pattern is employed to shape the GelMA hydrogel into customized geometry replicating individual wound areas, and thus both adhesion and antiadhesion properties are integrated into the same patch. In addition, vascular endothelial growth factor is loaded to accelerate the healing process. Based on these advantages, the authors demonstrate that the present patches not only adhere to different skin surfaces, but also promote the treatment of a rat cutaneous wound model. Thus, it is believed that this versatile patch can break through the limitation of traditional patches and be ideal candidates for wound healing and related biomedical applications.

Observation on Nursing Effect of Nano Trauma Patch for Intravenous Indwelling Needle Fixation

With the continuous research and advancement of medical nursing, the application of intravenous indwelling needles is becoming more and more widespread. As a new type of nano material, the nano wound patch can be effectively used in clinical applications. The purpose of this article is to explore the nursing effect observation of nana-wound patch for intravenous indwelling needle fixation. This article uses a survey method to investigate 300 inpatients admitted to a key hospital in a province and randomly divide them into an observation group and a control group. The types and severity of the diseases in each group are basically the same. By observing the patient's condition, statistics of experimental data. Experimental data showed that 77.33% of the patients in the observation group had no obvious displacement, deputation and obstruction after more than 72 h. At the same time, 72% of the patients in the observation group had no obvious local skin paleness, swelling, rash, and swelling and bruising. In terms of comfort, 81.33% of the patients in the observation group reported that they were more comfortable with no significant discomfort. In addition, 61.33% of the patients in the observation group could significantly prolong the venous indwelling needle indwelling time. In terms of the overall nursing effect, the effect of the nano-wound patch has increased by about 10–20%, but 50% of the patients in the observation group have a low acceptance of the nano-wound patch, which is mainly compared with the cost of the ordinary intravenous infusion patch compared with the nano-wound patch. Relatively high. Experimental data show that the nano wound patch effectively reduces the adverse reactions caused by intravenous indwelling needles, the adverse reaction rate is reduced by about 20%, and the indwelling time of intravenous indwelling needles is prolonged. On the other hand, it was found that the nano-wound patch has better nursing effect for fixed intravenous indwelling needles, and has guiding significance for the development of intravenous injection.

Light-controlled growth factors release on tetrapodal ZnO-incorporated 3D-printed hydrogels for developing smart wound scaffold.

Advanced wound scaffolds that integrate active substances to treat chronic wounds have gained significant recent attention. While wound scaffolds and advanced functionalities have previously been incorporated into one medical device, the wirelessly triggered release of active substances has remained the focus of many research endeavors. To combine multiple functions including light-triggered activation, anti-septic, angiogenic, and moisturizing properties, we have developed a 3D printed hydrogel patch encapsulating vascular endothelial growth factor (VEGF) decorated with photoactive and antibacterial tetrapodal zinc oxide (t-ZnO) microparticles. To achieve the smart release of VEGF, t-ZnO was modified by chemical treatment and activated through UV/visible light exposure. This process would also make the surface rough and improve protein adhesion. The elastic modulus and degradation behavior of the composite hydrogels, which must match the wound healing process, were adjusted by changing t-ZnO concentrations. The t-ZnO-laden composite hydrogels can be printed with any desired micropattern to potentially create a modular elution of various growth factors. The VEGF decorated t-ZnO-laden hydrogel patches showed low cytotoxicity and improved angiogenic properties while maintaining antibacterial functions in vitro. In vivo tests showed promising results for the printed wound patches, with less immunogenicity and enhanced wound healing.

A "sweet" way to increase the metabolic activity and migratory response of cells associated with wound healing: deoxy-sugar incorporated polymer fibres as a bioactive wound patch.

The selection of a wound dressing is crucial for successful wound management. Conventional dressings are preferable for the treatment of simple wounds. However, a bioactive wound dressing that supports wound management and accelerates the healing process is required when it comes to treating non-self-healing wounds. 2-deoxy-D-ribose (2dDR) is a small deoxy sugar that naturally occurs in human body. Although we have previously demonstrated that 2dDR can be used to induce neovascularisation and accelerates wound healing in vitro and in vivo, the literature on small sugars is conflicting, and the knowledge on how 2dDR achieves its biological activity is very limited. In this study, several small sugars including D-glucose (DG), 2-deoxy-D-glucose (2dDG), 2deoxy-L-ribose (2dLR) were compared to 2dDR by investigating their effects on the metabolic activities of both human dermal microvascular endothelial cells (HDMECs) and human dermal fibroblasts (HDFs). Then, for the first time, a two-dimensional (2D) scratch wound healing model was used to explore the migratory response of HDFs in response to 2dDR treatment. Finally, 2dDR was incorporated into Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) polymer fibres via electrospinning, and the metabolic activity of both types of cells in vitro was investigated in response to sugar release via Alamar Blue assay. The results demonstrated that 2dDR was the only sugar, among others, that enhances the metabolic activity of both HDMECs and HDFs and the migratory response of HDFs in a 2D scratch assay in a dose-dependent manner. In addition to direct administration, 2dDR was also found to increase the metabolic activity of HDMECs and HDFs over 7 days when released from polymer fibres. It is concluded that 2dDR is a potential pro-angiogenic agent that has a positive impact not only on endothelial cells but also fibroblasts, which take a key role in wound healing. It could easily be introduced into polymeric scaffolds to be released quickly to enhance the metabolic activity and the migratory response of cells that are associated with angiogenesis and wound healing.

Wound with Diabetes: Present Scenario and Future.

Diabetes is a chronic metabolic disorder of the endocrine system characterized by an increase in blood glucose level. Several factors, such as pancreatic damage, oxidative stress, infection, genetic factor, obesity, liver dysfunction, play a vital role in the pathogenesis of diabetes, which further leads to serious diabetic complications. The diabetic wound is one such complication where the wound formation occurs, especially due to pressure and its healing process is disrupted due to factors, such as hyperglycemia, neuropathy, nephropathy, peripheral vascular disease, reduction of blood flow, atherosclerosis, impaired fibroblast. The process of wound healing is delayed due to different abnormalities like alteration in nitric oxide level, increase in aldose reductase, sorbitol, and fructose. Therefore, diabetic wound requires more time to heal as compared to the normal wound. Healing time is delayed in diabetic wound due to many factors, such as stress, decreased oxygenation supply, infection, decreased blood flow, impaired proliferation and migration rate, impaired growth factor production, impaired keratinocytes proliferation and migration, and altered vascular endothelial mediators. The current treatment for diabetic wounds includes wound patches, oxygenation therapy, hydrogel patches, gene therapy, laser therapy, and stem cell therapy. Medications with phytoconstituents are also one way to manage the diabetic wound, but it is not more effective for quick healing. The objective of this review is to understand the potential of various management options which are available for diabetic wound, with a special focus on biological cells.

Multilayer Alginate-Polycaprolactone Electrospun Membranes as Skin Wound Patches with Drug Delivery Abilities.

A multilayer nanofibrous membrane consisting of a layer of polycaprolactone and one of physically cross-linked alginate-embedding ZnO nanoparticles is prepared via electrospinning technique as potential wound healing patches with drug delivery capabilities. A washing–cross-linking protocol is developed to obtain stable materials at the same time removing poly(ethylene oxide), which was used here as a cospinning agent for alginate, without interfering with the membrane’s peculiar nanofibrous structure. The mechanical behavior of the samples is assessed via a uniaxial tensile test showing appropriate resistance and manageability together with a good thermal stability as proved via thermogravimetric analysis. The polycaprolactone external layer enriches the samples with good liquid-repellent properties, whereas the alginate layer is able to promote tissue regeneration owing to its capability to promote cell viability and allow exudate removal and gas exchanges. Moreover, using methylene blue and methyl orange as model molecules, promising drug delivery abilities are observed for the mats. Indeed, depending on the nature and on the dye-loading concentration, the release kinetic can be easily tuned to obtain a slow controlled or a fast burst release. Consequently, the proposed alginate–polycaprolactone membrane represents a promising class of innovative, simple, and cost-effective wound healing patches appropriate for large-scale production.

Polymer-Assisted In Situ Synthesis of Silver Nanoparticles with Epigallocatechin Gallate (EGCG) Impregnated Wound Patch Potentiate Controlled Inflammatory Responses for Brisk Wound Healing.

IntroductionAn ideal wound dressing material needs to be predisposed with desirable attributes like anti-infective effect, skin hydration balance, adequate porosity and elasticity, high mechanical strength, low wound surface adherence, and enhanced tissue regeneration capability. In this work, we have synthesized hydrogel-based wound patches having antibacterial silver nanoparticles and antioxidant epigallocatechin gallate (EGCG) and showed fast wound closure through their synergistic interaction without any inherent toxicity.Methods and resultsWound patches were synthesized from modified guar gum polymer and assessed to determine accelerated wound healing. The modified polymer beget chemical-free in-situ synthesis of monodispersed silver NPs (~12 nm), an antimicrobial agent, besides lending ionic surface charges. EGCG impregnated during ionotropic gelation process amplified the efficacy of wound patches that possess apt tensile strength, porosity, and swellability for absorbing wound exudates. Further, in vitro studies endorsed them as non-cytotoxic and the post agent effect following exposure to the patch showed an unbiased response to E coli K12 and B. subtilis. In vivo study using sub-cutaneous wounds in Wistar rats validated its accelerated healing properties when compared to a commercially available wound dressing material (skin graft; Neuskin-F®) through better wound contraction, promoted collagen deposition and enhanced vascularization of wound region by modulating growth factors and inflammatory cytokines.ConclusionSynthesized wound patches showed all the desired attributes of a clinically effective dressing material and the results were validated in various in vitro and in vivo assays.

Delivery of RALA/siFKBPL nanoparticles via electrospun bilayer nanofibres: An innovative angiogenic therapy for wound repair

FK506-binding protein-like (FKBPL) has previously been shown to inhibit angiogenesis viain vitro and in vivo experimentation. Thus, it was proposed that the delivery of a siRNA targeting FKBPL could hold great potential in promoting angiogenesis for advanced wound healing applications. An effective delivery system has been utilised to encapsulate the siFKBPL to form nanoparticles, thereby improving cellular entry and eliciting a potent angiogenic response. In this study, nanoparticles were formed via condensation of siFKBPL with RALA; a novel, cationic 30 mer amphipathic peptide. Nanoparticles prepared at a N:P ratio of 6 demonstrated an average particle size of 76.6nm with a zeta potential of +16.5mV. Treatment of HMEC-1 cells at N:P 6 resulted in a transfection efficiency of 33.7%, negligible cytotoxicity, and significant knockdown of endogenous FKBPL expression. Functionally, treatment with RALA/siFKBPL resulted in significant improvements in cell migration and endothelial tubule formation in vitro. The process of electrospinning was employed to fabricate a nanofibrous wound patch to facilitate the controlled delivery of the RALA/siFKBPL nanoparticles. Alginate/poly-(vinyl alcohol) was electrospun following electrospinning of Chitosan/poly-(vinyl alcohol) to form a bilayered wound patch. Subsequently, the nanofibres were crosslinked to improve stability, before nanoparticle incorporation via soak loading. In vivo wound healing studies using C57BL/6J mice demonstrated a significant increase in angiogenesis when the RALA/siFKBPL nanoparticles were delivered from the bilayered wound patch; a 326% increase in blood vessel density was observed compared to untreated wounds. Taken together, this data demonstrates that delivery of RALA/siFKBPL nanoparticles from the bilayered wound patch represents an innovative wound healing therapy.

Crosslinking dextran electrospun nanofibers via borate chemistry: Proof of concept for wound patches

Dextran-based formulations represent promising candidates for the fabrication of biocompatible scaffolds in tissue engineering or as vehicles for drug delivery. Previous investigations showed that, on its own, dextran is able to promote wound healing in vivo in rat models. Its inherent solubility in water, however, must be overcome by inserting inter-molecular junctions via the use of cross-linkers. While conventional cross-linking methods tend to utilize toxic compounds, such as glutaraldehyde, we demonstrate that simple mixtures of dextran and boric acid, in aqueous solutions, can be electrospun to obtain membranes with controlled degradation times. Boric acid covalently links to the hydroxyls moieties present in the dextran chains yielding boronate ester bridges between dextran chains. Variation in the cross-linking density enhanced the average drug release time up to 500% compared to pristine dextran electrospun scaffolds.

Artificial, Triple-Layered, Nanomembranous Wound Patch for Potential Diabetic Foot Ulcer Intervention.

The present work aims to electrospin a triple layered wound patch for potential treatment of diabetic foot ulcers (DFU). The patch consisted of poly(acrylic acid) (PAA) as the skin contacting layer, polyvinyl pyrrolidone (PVP) as the middle layer, and polycaprolactone (PCL) as the outermost layer, wherein the PVP layer was loaded in situ with an antibiotic (ciprofloxacin, CFX). Morphology and mechanical properties were investigated using SEM and texture analysis. Patch quality was studied with regards to wettability, adherence, water resistance, and moisture uptake of individual layers. SEM results confirmed the fibrous and membranous nature of layers with a nano-to-micro size range. Mechanical properties of the composite patch demonstrated a tensile strength of 12.8 ± 0.5 MPa, deformation energy of 54.35 ± 0.1 J/m3, and resilience of 17.8 ± 0.7%, which were superior compared to individual layers. Patch quality tests revealed that the PCL layer showed very low wettability, adherence, and moisture uptake compared to the PVP and PAA layers. In vitro drug release data revealed an increase in cumulative drug release with higher drug loading. The results above confirm the potential of a triple layered, tripolymeric, wound patch for DFU intervention.

Plasma-Activated Substrate with a Tropoelastin Anchor for the Maintenance and Delivery of Multipotent Adult Progenitor Cells.

Conventional wound therapy utilizes wound coverage to prevent infection, trauma, and fluid and thermal loss. However, this approach is often inadequate for large and/or chronic wounds, which require active intervention via therapeutic cells to promote healing. To address this need, a patch which delivers multipotent adult progenitor cells (MAPCs) is developed. Medical-grade polyurethane (PU) films are modified using plasma immersion ion implantation (PIII), which creates a radical-rich layer capable of rapidly and covalently attaching biomolecules. It is demonstrated that a short treatment duration of 400 s maximizes surface activation and wettability, minimizes reduction in gas permeability, and preserves the hydrolytic resistance of the PU film. The reactivity of PIII-treated PU is utilized to immobilize the extracellular matrix protein tropoelastin in a functional conformation that stably withstands medical-grade ethylene oxide sterilization. The PIII-treated tropoelastin-functionalized patch significantly promotes MAPC adhesion and proliferation over standard PU, while fully maintaining cell phenotype. Topical application of the MAPC-seeded patch transfers cells to a human skin model, while undelivered MAPCs repopulate the patch surface for subsequent cell transfer. The potential of this new wound patch as a reservoir for the sustained delivery of therapeutic MAPCs and cell-secreted factors for large and/or non-healing wounds is indicated in the findings.