A bioartificial dermal regeneration template promotes skin cell proliferation in vitro and enhances large skin wound healing in vivo

Collagen as a Biomaterial for Skin and Corneal Wound Healing

The cornea and the skin are two organs that form the outer barrier of the human body. When either is injured (e.g., from surgery, physical trauma, or chemical burns), wound healing is initiated to restore integrity. Many cells are activated during wound healing. In particular, fibroblasts that are stimulated often transition into repair fibroblasts or myofibroblasts that synthesize extracellular matrix (ECM) components into the wound area. Control of wound ECM deposition is critical, as a disorganized ECM can block restoration of function. One of the most abundant structural proteins in the mammalian ECM is collagen. Collagen type I is the main component in connective tissues. It can be readily obtained and purified, and short analogs have also been developed for tissue engineering applications, including modulating the wound healing response. This review discusses the effect of several current collagen implants on the stimulation of corneal and skin wound healing. These range from collagen sponges and hydrogels to films and membranes.

Unique way of chest wall reconstruction using Integra Dermal Regeneration Template (IDRT) in a patient with post traumatic mucormycosis: A case report

INTRODUCTION AND IMPORTANCE

Necrotizing soft tissue infections (NSTI) are caused by toxin-producing bacteria and fungi that results in rapid progression of disease with significant local tissue destruction.

CASE PRESENTATION

We present a case report of a 57-year-old male patient in line with the SCARE 2020 criteria. He was admitted to the emergency department with a small abrasion on the right antero-lateral chest wall, and a diffuse necrotic patch of skin and soft tissues with purulent discharge.

CLINICAL DISCUSSION

Clinical examination, routine blood investigations, CT scan chest, and chest x-ray were performed. Patient underwent debridement six times, followed by negative pressure wound therapy (NPWT). After negative culture report, Integra Meshed Dermal Regeneration Template (IMDRT), measuring 4 × 5 in. was applied and NPWT continued. The outer layer of IDRT was removed on Day 19. Split thickness skin grafting (STSG) was performed once neodermis formation was confirmed. NPWT was continued post skin grafting for a week. IDRT was successfully taken up over the raw area with exposed lung. Patient was discharged 10 days after STSG. The patient's condition improved remarkably and he was able to breathe normally. There was no puckering or tethering effect on the grafted area and not much fibrosis. He showed speedy recovery with healed donor site and 100% uptake of grafted tissue.

CONCLUSION

IDRT along with NPWT is an effective and useful technique for spontaneous regeneration of the dermis and basement membrane to promote wound healing in traumatic patients with NSTIs.

LEVEL OF EVIDENCE

Level V.

STUDY TYPE

Therapeutic.

Effects of dipotassium glycyrrhizinate on wound healing

PURPOSE

Dipotassium glycyrrhizinate (DPG) has anti-inflammatory properties, besides promoting the regeneration of skeletal muscle. However, it has not been reported on skin wound healing/regeneration. This research aimed to characterize the effects of DPG in the treatment of excisional wounds by second intention.

METHODS

Male adults (n=10) and elderly (n=10) Wistar rats were used. Two circular wounds were excised on the dorsal skin. The excised normal skins were considered adult (GAN) and elderly (GIN) naïve. For seven days, 2% DPG was applied on the proximal excision: treated adult (GADPG) and elderly (GIDPG), whereas distal excisions were untreated adult (GANT) and elderly (GINT). Wound healing areas were daily measured and removed for morphological analyses after the 14th and the 21st postoperative day. Slides were stained with hematoxylin-eosin, Masson's trichrome, and picrosirius red.

RESULTS

Histological analysis revealed intact (GAN/GIN) and regenerated(GANT/GINT/GADPG/GIDPG) skins. No differences of wounds' size were found among treated groups. Epidermis was thicker after 14 days and thinner after 21 days of DPG administration. Higher collagen I density was found in GIDPG (14th day) and GADPG (21st day).

CONCLUSIONS

DPG induced woundhealing/skin regeneration, with collagen I, being more effective in the first 14 days after injury.

Preparation of biocompatible wound dressings with dual release of antibiotic and platelet-rich plasma for enhancing infected wound healing

The ever-growing threats of bacterial infection and chronic wound healing have provoked an urgent need for novel antibacterial wound dressings. In this study, we developed a wound dressing for the treatment of infected wounds, which can reduce the inflammatory period (through the use of gentamycin sulfate (GS)) and enhance the granulation stage (through the addition of platelet-rich plasma (PRP)). Herein, the sustained antimicrobial CMC/GMs@GS/PRP wound dressings were developed by using gelatin microspheres (GMs) loading GS and PRP, covalent bonding to carboxymethyl chitosan (CMC). The prepared dressings exhibited high water uptake capability, appropriate porosity, excellent mechanical properties, sustain release of PRP and GS. Meanwhile, the wound dressing showed good biocompatibility and excellent antibacterial ability against Gram-negative and Gram-positive bacteria. Moreover, in vivo experiments further demonstrated that the prepared dressings could accelerate the healing process of E. coli and S. aureus-infected full-thickness wounds in vivo, reepithelialization, collagen deposition and angiogenesis. In addition, the treatment of CMC/GMs@GS/PRP wound dressing could reduce bacterial count, inhibit pro-inflammatory factors (TNF-α, IL-1β and IL-6), and enhance anti-inflammatory factors (TGF-β1). The findings of this study suggested that biocompatible wound dressings with dual release of GS and PRP have great potential in the treatment of chronic and infected wounds.

Synergistic Effect of Chitosan and Selenium Nanoparticles on Biodegradation and Antibacterial Properties of Collagenous Scaffolds Designed for Infected Burn Wounds

A highly porous scaffold is a desirable outcome in the field of tissue engineering. The porous structure mediates water-retaining properties that ensure good nutrient transportation as well as creates a suitable environment for cells. In this study, porous antibacterial collagenous scaffolds containing chitosan and selenium nanoparticles (SeNPs) as antibacterial agents were studied. The addition of antibacterial agents increased the application potential of the material for infected and chronic wounds. The morphology, swelling, biodegradation, and antibacterial activity of collagen-based scaffolds were characterized systematically to investigate the overall impact of the antibacterial additives. The additives visibly influenced the morphology, water‑retaining properties as well as the stability of the materials in the presence of collagenase enzymes. Even at concentrations as low as 5 ppm of SeNPs, modified polymeric scaffolds showed considerable inhibition activity towards Gram-positive bacterial strains such as Staphylococcus aureus and methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis in a dose-dependent manner.

Análise ultraestrutural do colágeno de feridas cutâneas de coelhos tratadas com plasma rico em plaquetas de equino

RESUMO O colágeno é sintetizado e segregado no espaço extracelular e organizados em fibrilas estriadas de acordo com o tipo de tecido. Utilizaram-se 24 coelhos brancos da raça Nova Zelândia, com idade de 12 meses e com 3,0kg de peso corporal, para avaliar a porcentagem de colágeno das feridas cutâneas tratadas com plasma rico em plaquetas de equino e pomada contendo gentamicina, sulfanilamida, sulfadiazina, ureia e vitamina A. Os animais foram separados em quatro grupos de igual número e submetidos à remoção de pele na região das linhas médias dorsal torácica (feridas tratadas) e lombar (feridas controle). As feridas torácicas foram tratadas com plasma rico em plaqueta de equino e pomada contendo gentamicina, sulfanilamida, sulfadiazina, ureia e vitamina A, e as do grupo controle somente com a pomada. Dos animais do grupo I, foi coletado tecido cutâneo, para a avaliação histológica e a ultraestrutural, com três dias de pós-operatório; dos animais do grupo II, com sete dias; do grupo III, com 14 dias; e do grupo IV, com 21 dias. Decorrido o período de avaliação de cada grupo, foi coletado fragmento de pele para avaliação da porcentagem de colágeno, bem como do diâmetro e da densidade da fibrila de colágeno por microscopia eletrônica de transmissão. O tratamento com PRP de equino associado à aplicação tópica da pomada mostrou-se eficaz na maturação das fibrilas colágenas e na antecipação do processo cicatricial.

Efficacy of application of Equisetum pyramidale Goldm. hydrogel for tissue restoration of induced skin lesions in Wistar rats

Medicinal plants, such as E. pyramidale, are alternatives against infections and assist in the healing process of wounds. We evaluated the effects of Hydrogel of E. pyramidale on the healing of cutaneous wounds in animal models by morphological, morphometric and histological analyses, and elucidated major components. The ethanolic extract of E. pyramidale shoots was submitted to phytochemical analysis. For cicatrizing activity assay, Wistar rats were used, and the groups evaluated were hydrogel containing ethanolic extract of E. pyramidale at 2% compared to control groups. The treatment periods were 3, 7 and 21 days, and macroscopic and microscopic analyses were performed. Data were submitted to Analysis of Variance (p <0.05). Phytochemistry and quantification evidenced that flavonoids are main constituents and that they were evidenced by thin layer chromatography (TLC), high efficiency (HPLC) and infrared (IR) methods. In TLC, using flavonoid patterns, we observed pinocembrin. The hydrogel containing ethanolic extract of E. pyramidale at 2% was effective in wound regression. E. pyramidale can be used for the treatment of second intention wounds, and the effective healing may be due to a high flavonoid content.

Co-treatment of wounds in rabbit skin with equine platelet-rich plasma and a commercial ointment accelerates healing

Abstract Autologous platelet-rich plasma (PRP) is beneficial in the healing process of reconstructive surgeries, contributing to the stimulation of angiogenesis; however, heterologous plasma has been shown to be more effective. The objective of this study was to verify, by macro- and microscopic evaluation, whether PRP accelerates the healing process as compared to a commercial ointment containing gentamicin, sulfanilamide, sulfadiazine, urea, and vitamin A (study ointment). This study used 24 white New Zealand rabbits, aged 12 months, and each weighing approximately 3 kg. The animals were separated into 4 equal groups and underwent wound induction through skin removal in the thoracic (study wound) and lumbar (control wound) dorsal midline. Study wounds were co-treated with equine PRP and the study ointment. Control wounds were treated with only the study ointment. Group I underwent histological evaluation 3 days after the skin removal procedure, group II after 7 days, group III after 14 days, and group IV after 21 days. A skin fragment was collected from each animal for histological evaluation. The co-treatment with heterologous equine PRP and the study ointment accelerated the healing process in the surgically induced skin wounds, confirming the acceleratory effect of PRP on wound healing.

A new nanoscale transdermal drug delivery system: oil body-linked oleosin-hEGF improves skin regeneration to accelerate wound healing

Background

Epidermal growth factor (EGF) can promote cell proliferation as well as migration, which is feasible in tissue wound healing. Oil bodies have been exploited as an important platform to produce exogenous proteins. The exogenous proteins were expressed in oil bodies from plant seeds. The process can reduce purification steps, thereby significantly reducing the purification cost. Mostly, the diameter of oil body particle ranges between 1.0 and 1.5 µm in the safflower seeds, however, it reduces to 700–1000 nm in the transgenic safflower seeds. The significant reduction of particle size in transgenic seeds is extremely beneficial to skin absorption.

Results

The diameter of oil body in the transgenic safflower seeds was recorded in the range of 700–1000 nm. The smaller particle size improved their skin absorption. The expression level of oleosin-hEGF-hEGF in T3 transgenic seeds was highest at 69.32 mg/g of seeds. The oil body expressing oleosin-hEGF-hEGF had significant proliferative activity on NIH/3T3 cells and improved skin regeneration thereby accelerating wound healing in rats. The wound coverage rate exceeded 98% after treatment for 14 days with oil body expressing oleosin-hEGF-hEGF, while the saline without EGF group and wild type oil body group both showed less than 80%. The neonatal fibroblast and collagen were found to be increased in the safflower oil body expressing oleosin-hEGF-hEGF treatment group. TGF-β1, bFGF and VEGF were noted as important growth factors in the repair of cutaneous wounds. Their expression level increased after 4 and 7 day treatment, but decreased after 14 days. Therefore, it can promote skin regeneration to accelerate wounds healing.

Conclusions

The expression of oleosin-hEGF-hEGF in T3 transgenic seeds was 80.43 ng/μL oil body. It had significant proliferative activity on NIH/3T3 cells and improved skin regeneration to accelerate wound healing in rats. The expression process of TGF-β1, bFGF and VEGF increased at first and then gradually declined.

Electronic supplementary material

The online version of this article (10.1186/s12951-018-0387-5) contains supplementary material, which is available to authorized users.