Porous silicon-based sensing and delivery platforms for wound management applications

Wound management remains a great challenge for clinicians due to the complex physiological process of wound healing. Porous silicon (PSi) with controlled pore morphology, abundant surface chemistry, unique photonic properties, good biocompatibility, easy biodegradation and potential bioactivity represent an exciting class of materials for various biomedical applications. In this review, we focus on the recent progress of PSi in the design of advanced sensing and delivery systems for wound management applications. Firstly, we comprehensively introduce the common type, normal healing process, delaying factors and therapeutic drugs of wound healing. Subsequently, the typical fabrication, functionalization and key characteristics of PSi have been summarized because they provide the basis for further use as biosensing and delivery materials in wound management. Depending on these properties, the rise of PSi materials is evidenced by the examples in literature in recent years, which has emphasized the robust potential of PSi for wound monitoring, treatment and theranostics. Finally, challenges and opportunities for the future development of PSi-based sensors and delivery systems for wound management applications are proposed and summarized. We hope that this review will help readers to better understand current achievements and future prospects on PSi-based sensing and delivery systems for advanced wound management.

Biomimetic Materials for Skin Tissue Regeneration and Electronic Skin

Biomimetic materials have become a promising alternative in the field of tissue engineering and regenerative medicine to address critical challenges in wound healing and skin regeneration. Skin-mimetic materials have enormous potential to improve wound healing outcomes and enable innovative diagnostic and sensor applications. Human skin, with its complex structure and diverse functions, serves as an excellent model for designing biomaterials. Creating effective wound coverings requires mimicking the unique extracellular matrix composition, mechanical properties, and biochemical cues. Additionally, integrating electronic functionality into these materials presents exciting possibilities for real-time monitoring, diagnostics, and personalized healthcare. This review examines biomimetic skin materials and their role in regenerative wound healing, as well as their integration with electronic skin technologies. It discusses recent advances, challenges, and future directions in this rapidly evolving field.

Functionalised biomaterials as synthetic extracellular matrices to promote vascularisation and healing of diabetic wounds

Diabetic foot ulcers (DFU) are a type of chronic wound that constitute one of the most serious and debilitating complications associated with diabetes. The lack of clinically efficacious treatments to treat these recalcitrant wounds can lead to amputations for those worst affected. Biomaterial-based approaches offer great hope in this regard, as they provide a template for cell infiltration and tissue repair. However, there is an additional need to treat the underlying pathophysiology of DFUs, in particular insufficient vascularization of the wound which significantly hampers healing. Thus, the addition of pro-angiogenic moieties to biomaterials is a promising strategy to promote the healing of DFUs and other chronic wounds. In this review, we discuss the potential of biomaterials as treatments for DFU and the approaches that can be taken to functionalise these biomaterials such that they promote vascularisation and wound healing in pre-clinical models.

Vital pulp therapy for permanent teeth with diagnosis of irreversible pulpitis: biological basis and outcome

Root canal treatment (RCT) has been considered the conventional standard for the management of teeth with carious pulp exposure, particularly in mature teeth presenting with symptoms. Following a better understanding of the histopathology of deep carious lesions, the histology of the cariously exposed pulp and the healing potential of the inflamed pulp, vital pulp therapy (VPT) is increasingly adopted around the world for the management of permanent teeth with clinical signs and symptoms indicative of irreversible pulpitis. Furthermore, VPT became a recognized treatment modality by the European Society of Endodontology (ESE) and the American Association of Endodontists (AAE) by virtue of its high success rates reported in outcome studies using contemporary hydraulic calcium silicate-based cements. However, proper case selection, strict asepsis, capping materials and good coronal seal are mandatory for success. The aim of this paper is to review the biological basis for VPT in symptomatic teeth with carious pulp exposure and to report on the outcome of pulpotomy in teeth with clinical diagnosis of irreversible pulpitis.

Skin Inflammation with a Focus on Wound Healing

Significance: The skin is the crucial first-line barrier against foreign pathogens. Compromise of this barrier presents in the context of inflammatory skin conditions and in chronic wounds. Skin conditions arising from dysfunctional inflammatory pathways severely compromise the quality of life of patients and have a high economic impact on the U.S. health care system. The development of a thorough understanding of the mechanisms that can disrupt skin inflammation is imperative to successfully modulate this inflammation with therapies. Recent Advances: Many advances in the understanding of skin inflammation have occurred during the past decade, including the development of multiple new pharmaceuticals. Mechanical force application has been greatly advanced clinically. Bioscaffolds also promote healing, while reducing scarring. Critical Issues: Various skin inflammatory conditions provide a framework for analysis of our understanding of the phases of successful wound healing. The large burden of chronic wounds on our society continues to focus attention on the chronic inflammatory state induced in many of these skin conditions. Future Directions: Better preclinical models of disease states such as chronic wounds, coupled with enhanced diagnostic abilities of human skin, will allow a better understanding of the mechanism of action. This will lead to improved treatments with biologics and other modalities such as the strategic application of mechanical forces and scaffolds, which ultimately results in better outcomes for our patients.

Examination of the effects of kefir on healing factors in a mice burn model infected with E.coli, S.aureus and P.aeruginosa using qRT-PCR

Burn areas are susceptible to bacterial growth and infections, particularly in cases with lengthy periods of hospital stay. Burn wound healing, which involves various molecular and cellular mechanisms, continues to be a significant problem. Growth factors and cytokines play an active and vital role in wound healing. In the present study, the effects of kefir on wound healing in a 2nd-degree mouse burn model infected with e.coli, s.aureus and p.aeruginosa were investigated in vitro. In order to clarify the effects of kefir in the wound healing process, the macroscopic changes in kefir-applied scar tissue as well as wound depth and width were examined and IL-1α, IL-1β, IL-6, IL-8, IL-10 and TNF-α, VEGF, TGF-β protein levels were determined using the qRT-PCR method. The findings of the present study show that kefir has a positive impact on the factors playing a role in wound healing and accelerates the healing process.

Mechano-biological and bio-mechanical pathways in cutaneous wound healing

Injuries to the skin heal through coordinated action of fibroblast-mediated extracellular matrix (ECM) deposition, ECM remodeling, and wound contraction. Defects involving the dermis result in fibrotic scars featuring increased stiffness and altered collagen content and organization. Although computational models are crucial to unravel the underlying biochemical and biophysical mechanisms, simulations of the evolving wound biomechanics are seldom benchmarked against measurements. Here, we leverage recent quantifications of local tissue stiffness in murine wounds to refine a previously-proposed systems-mechanobiological finite-element model. Fibroblasts are considered as the main cell type involved in ECM remodeling and wound contraction. Tissue rebuilding is coordinated by the release and diffusion of a cytokine wave, e.g. TGF-β, itself developed in response to an earlier inflammatory signal triggered by platelet aggregation. We calibrate a model of the evolving wound biomechanics through a custom-developed hierarchical Bayesian inverse analysis procedure. Further calibration is based on published biochemical and morphological murine wound healing data over a 21-day healing period. The calibrated model recapitulates the temporal evolution of: inflammatory signal, fibroblast infiltration, collagen buildup, and wound contraction. Moreover, it enables in silico hypothesis testing, which we explore by: (i) quantifying the alteration of wound contraction profiles corresponding to the measured variability in local wound stiffness; (ii) proposing alternative constitutive links connecting the dynamics of the biochemical fields to the evolving mechanical properties; (iii) discussing the plausibility of a stretch- vs. stiffness-mediated mechanobiological coupling. Ultimately, our model challenges the current understanding of wound biomechanics and mechanobiology, beside offering a versatile tool to explore and eventually control scar fibrosis after injury.

An Updated Review of Hypertrophic Scarring

Hypertrophic scarring (HTS) is an aberrant form of wound healing that is associated with excessive deposition of extracellular matrix and connective tissue at the site of injury. In this review article, we provide an overview of normal (acute) wound healing phases (hemostasis, inflammation, proliferation, and remodeling). We next discuss the dysregulated and/or impaired mechanisms in wound healing phases that are associated with HTS development. We next discuss the animal models of HTS and their limitations, and review the current and emerging treatments of HTS.

Xenogeneic mesenchymal stem cell biocurative improves skin wounds healing in diabetic mice by increasing mast cells and the regenerative profile

Introduction

Diabetes mellitus (DM) is a chronic disease and a major cause of mortality and morbidity worldwide. The hyperglycemia caused by DM induces micro and macrovascular complications that lead, among other consequences, to chronic wounds and amputations. Cell therapy and tissue engineering constitute recent therapeutic alternatives to improve wound healing in diabetic patients. The current study aimed to analyze the effectiveness of biocuratives containing human mesenchymal stem cells (MSCs) associated with a hydrogel matrix in the wound healing process and related inflammatory cell profile in diabetic mice.

Methods

Biocuratives containing MSCs were constructed by 3D bioprinting, and applied to skin wounds on the back of streptozotocin (STZ)-induced type 1 diabetic (T1D) mice. The healing process, after the application of biocuratives with or without MSCs was histologically analyzed. In parallel, genes related to growth factors, mast cells (MC), M1 and M2 macrophage profiles were evaluated by RT-PCR. Macrophages were characterized by flow cytometry, and MC by toluidine blue staining and flow cytometry.

Results

Mice with T1D exhibited fewer skin MC and delayed wound healing when compared to the non-diabetic group. Treatment with the biocuratives containing MSCs accelerated wound healing and improved skin collagen deposition in diabetic mice. Increased TGF-β gene expression and M2 macrophage-related markers were also detected in skin of diabetic mice that received MSCs-containing biocuratives. Finally, MSCs upregulated IL-33 gene expression and augmented the number of MC in the skin of diabetic mice.

Conclusion

These results reveal the therapeutic potential of biocuratives containing MSCs in the healing of skin wounds in diabetic mice, providing a scientific base for future treatments in diabetic patients.

Postoperatif peritoneal adhezyonların önlenmesinde saf zeytinyağı ve PRF’nin etkinliği

Purpose: In this study, we applied platelet rich fibrin (PRF) and pure olive oil on the incision surfaces of rats. We aimed to examine whether PRF may be used safely to prevent peritoneal adhesions. Materials and Methods: Fourty rats were divided into 4 groups (n=8). Eight rats, not included in the study groups, were used to obtain PRF material. Group 1 had no surgical procedure, Group 2 was operated without medication, Group 3 was operated and received 1cc olive oil, Group 4 was operated and received 1 cc PRF. After 21 days, cecum areas were examined histopathologically. Tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), intercellular adhesion molecule-1 (ICAM-1) and platelet-derived growth factor (PDGF) levels were measured in serum by ELISA. Results: The adhesion scores and severity of fibrosis in Group 3 and 4 were significantly lower than Group 2. Plasma TNF-α value was significantly higher in Group 2 than Group 4. Plasma PDGF value was significantly higher in Group 2 than Group 3 and 4. Discussion: PRF reduced intestinal adhesion by inhibiting the proliferation of fibroblasts and inflammatory cells, and promoting the proliferation of mesothelial cells. PRF has anti-inflammatory effect and prevented postop adhesions, based mainly on growth factors and cytokines in its content.

Multiwalled carbon nanotubes functionalized bacterial cellulose as an efficient healing material for diabetic wounds

The unique pool of features makes bacterial cellulose (BC) a robust platform to tailor its functionalities. Herein, the BC matrix was reinforced with multiwalled carbon nanotubes (MWCNT) to control infection and accelerate the healing process of diabetic wounds. The prepared BC-MWCNT composite film was characterized and antibacterial activity was assessed. Further, the in-vivo wound healing activity was performed and temporal expression of interleukin (IL-1α), tumor necrosis factor (TNF-α), vascular endothelial growth factor (VEGF) and platelets derived growth factor (PDGF) was quantitatively measured by real-time PCR. The characterization results confirmed the reinforcement of the BC matrix with MWCNT. The composite film showed antibacterial activity against all the tested strains. Moreover, the macroscopic analysis of the wound demonstrated faster closure of the diabetic wound in BC-MWCNT group (99% healing) as compared to negative control (77%) in 21 days. Histological studies further supported the results where complete reepithelization of the epidermis and healthy granulation tissue were observed in BC-MWCNT treated group. Molecular studies revealed that BC-MWCNT group showed relatively lesser expression of pro-inflammatory cytokines IL-1α and TNF-α and higher expression of VEGF than control that may have favored the faster healing. This study suggested that the tailorable properties of BC can be exploited to develop composites with potential applications in diabetic wound healing.

The effect of henna and linseed herbal ointment blend on wound healing in rats with second-degree burns

The treatment of skin burns is one of the most important challenge in medical science. The aim of this study is evaluation of the efficacy of Artaderm herbal ointment containing the Henna (Lawsonia inermis) extract, Linseed (Linum usitatissimum) oil, and Honey Wax on wound healing in the rat with second-degree burn wounds. The Artaderm ointment had an effective role in controlling burn wound infections due to its antimicrobial and anti-inflammatory properties. In this study, 64 male Wistar rats were randomly divided into 8 groups (n = 8). Four groups received Artaderm, 1% Silver Sulfadiazine (SSD 1%), Cod Liver Oil and Fundermol (Alpha) ointments which used in common practices for burn injuries. Another three groups received Henna, Linseed, and Honey Wax alone and a control group that just underwent a second-degree burn injury without any treatments. A second-degree burn was formed on the back of each rat and dressed daily with one of the agents. Burn wounds were macroscopically and microscopically evaluated on the 7th, 14th, and 21st day after burn induction. Rats treated with the Artaderm ointment had significantly faster wound contraction as well as shorter healing time than the rest groups. No scar was observed in rats treated with the Artaderm ointment on the 21st day, while this level of improvement was not observed in other groups at the same time. More than 90% of wounds were healed after on the 14th day in rats treated with Artaderm (94.10 ± 0.18) and Alpha (92.05 ± 0.23) ointments. According to these findings, it can be concluded that Artaderm herbal ointment can be used as a proper alternative for healing of wounds in second-degree burns.

Low mortality oxidative stress murine chronic wound model

INTRODUCTION

Investigators have struggled to produce a reliable chronic wound model. Recent progress with antioxidant enzyme inhibitors shows promise, but mortality rates are high. We modified the dosage and administration of an antioxidant enzyme inhibitor regimen to reduce mortality while inducing a chronic wound environment.

RESEARCH DESIGN AND METHODS

To chemically induce a chronic wound environment, we applied modified doses of catalase (3-amino-1,2,4-triazole; intraperitoneal 0.5 g/kg) and glutathione peroxidase (mercaptosuccinic acid; topical 300 mg/kg) inhibitors to the dorsal wounds of 11-week-old db/db mice. A cohort of these mice was treated with a collagen-glycosaminoglycan scaffold. Both groups were compared with Diabetic control mice.

RESULTS

This study successfully induced a chronic wound in 11-week-old db/db mice, with no animal deaths. The antioxidant enzyme treated groups showed delayed wound contraction and significantly higher levels of inflammatory tissue, collagen deposition, cellular proliferation and leukocyte infiltration than the Diabetic control group. Angiogenesis was significantly higher in the antioxidant enzyme treated groups, but the vessels were immature and friable. Scaffold engraftment was poor but appeared to promote blood vessel maturation.

CONCLUSIONS

Overall, the two in vivo groups treated with the antioxidant enzyme inhibitors appeared to be arrested in the inflammatory stage of wound healing, while the Diabetic control group progressed to the maturation phase and ultimately remodeling. This model may be instrumental for the development of new wound therapeutics.

Regeneration and Repair of Skin Wounds: Various Strategies for Treatment

Skin as a mechanical barrier between the inner and outer environment of our body protects us against infection and electrolyte loss. This organ consists of 3 layers: the epidermis, dermis, and hypodermis. Any disruption in the integrity of skin leads to the formation of wounds, which are divided into 2 main categories: acute wounds and chronic wounds. Generally, acute wounds heal relatively faster. In contrast to acute wounds, closure of chronic wounds is delayed by 3 months after the initial insult. Treatment of chronic wounds has been one of the most challenging issues in the field of regenerative medicine, promoting scientists to develop various therapeutic strategies for a fast, qualified, and most cost-effective treatment modality. Here, we reviewed more recent approaches, including the development of stem cell therapy, tissue-engineered skin substitutes, and skin equivalents, for the healing of complex wounds.

Vital pulp therapy: histopathology and histobacteriology-based guidelines to treat teeth with deep caries and pulp exposure

OBJECTIVES

Vital pulp therapy (VPT) encompasses distinct treatment modalities for deep caries that approximate the pulp chamber in vital teeth. Confusion exists in the literature in terms of the indication and rationale for each VPT approach. The objectives of the present study are to elucidate the indications for VPT and to present a set of histopathology and histobacteriology-based guidelines for VPT in teeth with deep caries.

METHODS

Two hundred and sixty-four carious, unrestored and VPT-treated human teeth, which were extracted for reasons not related to the present study. The teeth were processed for histological and histobacteriological examination. Other 757 clinical cases that received different VPT procedures were followed-up to identify success rates, with the longest observational period of 30 years.

RESULTS

Follow-up of the clinical cases indicated that direct pulp capping was successful in 73.2%, partial pulpotomy in 96.4% and full pulpotomy in 77.8% of the cases. Histological and histobacteriological examination showed a localised inflammatory response that commonly occurred in the subjacent pulp tissue as soon as the enamel was penetrated by caries. If the softened and infected dentine were completely excavated, without pulp exposure, and the cavity restored with an adequate restoration, pulp inflammation frequently subsided. In teeth showing pulp exposure, the extent of bacterial penetration varied and areas of infection presented severe pulp inflammation, including micro-abscesses. However, the pulp tissue apical to the infected/inflamed area was usually uninflamed and normal. Guidelines based on the present histopathological, histobacteriological and clinical findings are proposed for VPT and mainly involve direct examination of dentine and the exposed pulp tissue under deep caries for decision-making, and require strict asepsis during procedures.

CONCLUSIONS

Vital pulp therapy following the guidelines proposed in the present article has the potential to improve the outcome of the conservative treatment of mature teeth with deep caries and in some occasions may be an alternative to pulpectomy.

CLINICAL SIGNIFICANCE

A guideline for VPT in the treatment of deep caries is proposed, focusing on direct observation of dentine and the exposed pulp tissue under deep caries. Stringent aseptic techniques are mandatory for VPT procedures to be successful.

The Effect of Polydeoxyribonucleotide Extracted from Salmon Sperm on the Restoration of Bisphosphonate-Related Osteonecrosis of the Jaw

Bisphosphonates (BPs) used for treating skeletal diseases can induce bisphosphonate-related osteonecrosis of the jaw (BRONJ). Despite much effort, effective remedies are yet to be established. In the present study, we investigated the feasibility of polydeoxyribonucleotide (PDRN) extracted from salmon sperm for the treatment of BRONJ, in a BRONJ-induced rat model. Compared with BRONJ-induced samples, PDRN-treated samples exhibited lower necrotic bone percentages and increased numbers of blood vessels and attached osteoclast production. Moreover, local administration of PDRN at a high concentration (8 mg/kg) remarkably resolved the osteonecrosis. Findings from this study suggest that local administration of PDRN at a specific concentration may be considered clinically for the management of BRONJ.

Novel Biodegradable Polymeric Microparticles Facilitate Scarless Wound Healing by Promoting Re-epithelialization and Inhibiting Fibrosis

Despite decades of research, the goal of achieving scarless wound healing remains elusive. One of the approaches, treatment with polymeric microcarriers, was shown to promote tissue regeneration in various in vitro models of wound healing. The in vivo effects of such an approach are attributed to transferred cells with polymeric microparticles functioning merely as inert scaffolds. We aimed to establish a bioactive biopolymer carrier that would promote would healing and inhibit scar formation in the murine model of deep skin wounds. Here we characterize two candidate types of microparticles based on fibroin/gelatin or spidroin and show that both types increase re-epithelialization rate and inhibit scar formation during skin wound healing. Interestingly, the effects of these microparticles on inflammatory gene expression and cytokine production by macrophages, fibroblasts, and keratinocytes are distinct. Both types of microparticles, as well as their soluble derivatives, fibroin and spidroin, significantly reduced the expression of profibrotic factors Fgf2 and Ctgf in mouse embryonic fibroblasts. However, only fibroin/gelatin microparticles induced transient inflammatory gene expression and cytokine production leading to an influx of inflammatory Ly6C+ myeloid cells to the injection site. The ability of microparticle carriers of equal proregenerative potential to induce inflammatory response may allow their subsequent adaptation to treatment of wounds with different bioburden and fibrotic content.

Regulation of connexin 43 expression in human gingival fibroblasts

AIMS

Abundance of connexin 43 (Cx43), a transmembrane protein that forms hemichannels (HCs) and gap junctions (GJs), is dynamically regulated in human gingival fibroblasts (GFBLs) during wound healing. This may be important for fast and scarless gingival wound healing as Cx43 is involved in key cell functions important during this process. Our aim was to uncover the factors that regulate Cx43 expression and abundance in GFBLs. We hypothesized that cytokines and growth factors released during wound healing coordinately regulate Cx43 abundance in GFBLs.

RESULTS

TGF-β1, -β2, -β3, PGE2 and IL-1β significantly upregulated, while TNF-α and IFN-γ downregulated Cx43 in cultured GFBLs. TGF-β1, -β2, -β3, IL-1β and IFN-γ modulated Cx43 abundance at both mRNA and protein levels, while TNF-α and PGE2 regulated only Cx43 protein abundance, suggesting involvement of distinct transcriptional/post-transcriptional and translational/post-translational mechanisms, respectively. TGF-β1-induced upregulation of Cx43 was mediated by TGFβRI (ALK5) and SMAD2/3 signaling, and this was potently suppressed by PGE2, IL-1β, TNF-α and IFN-γ that inhibited SMAD2/3 phosphorylation.

CONCLUSION

Regulation of Cx43 abundance in GFBLs involves transcriptional/post-transcriptional and translational/post-translational mechanisms that are distinctly modulated by an interplay between TGF-β isoforms and PGE2, IL-1β, TNF-α and IFN-γ.

The reduction in inflammation and impairment in wound healing by using strontium chloride hexahydrate

BACKGROUND

Numerous growth factors, cytokine, mitogen and chemotactic factors are involved in wound healing. Even though inflammation is important for the stimulation of proliferative phase, excessive inflammation also causes impairment in wound healing. Strontium salts suppress keratinocyte-induced TNF-alpha and interleukin-1 and interleukin-6 in in vitro cultures. This study was conducted to determine the effects of administration of topical strontium chloride hexahydrate on wound healing through TNF-alpha and TGF-beta in surgical wound healing model of in-vivo rat skin.

MATERIAL AND METHODS

Twenty-four rats were used in the study. After approximately 2 cm cutaneous-subcutaneous incision was horizontally carried out on the mid-neckline of the rats, the incision was again closed using 2.0 vicryl. The rats were assigned into three groups including eight rats in each group. Placebo emollient ointment and also the ointments, which were containing 5% and 10% strontium chloride hexahydrate and were prepared at the same base with placebo ointment, were administered to the groups by a blind executor twice a day for a week. At the end of seventh day, the rats were sacrificed and cutaneous and subcutaneous tissue of their wound site was resected for histopathological examination. Scoring of histopathological wound healing and scoring of tissue TNF-alpha and TGF-beta level with immunohistochemical staining were performed.

RESULTS

The groups, to which both 5% and 10% strontium chloride hexahydrate was administered, had lower immunohistochemical TNF-alpha levels and histopathological wound scores compared to controls, which was statistically significant (p < 0.05).

CONCLUSION

Strontium chloride hexahydrate can lead to impairment in wound healing by suppressing inflammation through TNF-alpha.

Ibuprofen loaded PLA nanofibrous scaffolds increase proliferation of human skin cells in vitro and promote healing of full thickness incision wounds in vivo

This article presents successful incorporation of ibuprofen in polylactic acid (PLA) nanofibers to create scaffolds for the treatment of both acute and chronic wounds. Nanofibrous PLA scaffolds containing 10, 20, or 30 wt % ibuprofen were created and ibuprofen release profiles quantified. In vitro cytotoxicity to human epidermal keratinocytes (HEK) and human dermal fibroblasts (HDF) of the three scaffolds with varying ibuprofen concentrations were evaluated and compared to pure PLA nanofibrous scaffolds. Thereafter, scaffolds loaded with ibuprofen at the concentration that promoted human skin cell viability and proliferation (20 wt %) were evaluated in vivo in nude mice using a full thickness skin incision model to determine the ability of these scaffolds to promote skin regeneration and/or assist with scarless healing. Both acellular and HEK and HDF cell-seeded 20 wt % ibuprofen loaded nanofibrous bandages reduced wound contraction compared with wounds treated with Tegaderm™ and sterile gauze. Newly regenerated skin on wounds treated with cell-seeded 20 wt % ibuprofen bandages exhibited significantly greater blood vessel formation relative to acellular ibuprofen bandages. We have found that degradable anti-inflammatory scaffolds containing 20 wt % ibuprofen promote human skin cell viability and proliferation in vitro, reduce wound contraction in vivo, and when seeded with skin cells, also enhance new blood vessel formation. The approaches and results reported here hold promise for multiple skin tissue engineering and wound healing applications. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 327-339, 2017.

Integrins in Wound Healing

Significance: Regulation of cell adhesions during tissue repair is fundamentally important for cell migration, proliferation, and protein production. All cells interact with extracellular matrix proteins with cell surface integrin receptors that convey signals from the environment into the nucleus, regulating gene expression and cell behavior. Integrins also interact with a variety of other proteins, such as growth factors, their receptors, and proteolytic enzymes. Re-epithelialization and granulation tissue formation are crucially dependent on the temporospatial function of multiple integrins. This review explains how integrins function in wound repair. Recent Advances: Certain integrins can activate latent transforming growth factor beta-1 (TGF-β1) that modulates wound inflammation and granulation tissue formation. Dysregulation of TGF-β1 function is associated with scarring and fibrotic disorders. Therefore, these integrins represent targets for therapeutic intervention in fibrosis. Critical Issues: Integrins have multifaceted functions and extensive crosstalk with other cell surface receptors and molecules. Moreover, in aberrant healing, integrins may assume different functions, further increasing the complexity of their functionality. Discovering and understanding the role that integrins play in wound healing provides an opportunity to identify the mechanisms for medical conditions, such as excessive scarring, chronic wounds, and even cancer. Future Directions: Integrin functions in acute and chronic wounds should be further addressed in models better mimicking human wounds. Application of any products in acute or chronic wounds will potentially alter integrin functions that need to be carefully considered in the design.