Acceleration Mechanisms of Skin Wound Healing by Autologous Micrograft in Mice

Efficacy of Chinese and Western Medical Techniques in Treating Diabetic Foot Ulcers With Necrotizing Fasciitis of the Lower Leg

To analyze and evaluate the clinical efficacy of Chinese and Western medical techniques in the treatment of severe diabetic foot ulcers complicated with necrotizing fasciitis of the lower leg and summarize the treatment experience of such patients to identify a new method of limb salvage treatment. A total of 46 patients with severe diabetic foot ulcers and necrotizing fasciitis of the lower leg were treated with such techniques as surgical debridement, bone drilling, open joint fusion, and microskin implantation. Wounds were treated with moisture-exposed burn therapy (a regenerative medical treatment for burns, wounds, and ulcers) and moisture-exposed burn ointment (a traditional Chinese medicine); underlying diseases were also treated effectively. The wound healing time, rate of high amputation, and mortality of these patients were summarized, and the clinical efficacy of such treatments was evaluated. Of the 46 patients enrolled, 38 patients were cured, with a cure rate of 82.61%. The average wound healing time was 130 ± 74.37 days. Two patients underwent high amputations, with an amputation rate of 4.35%, and 4 deaths occurred, with a mortality rate of 8.70%. The combination of Chinese and Western medical techniques in the treatment of severe diabetic foot ulcers complicated with necrotizing fasciitis of the lower leg not only effectively saved patients' lives and promoted wound healing but also greatly reduced the rates of high amputation and disability.

Biomaterials derived from hard palate mucosa for tissue engineering and regenerative medicine

Autologous materials have superior biosafety and are widely used in clinical practice. Due to its excellent trauma-healing ability, the hard palate mucosa (HPM) has become a hot spot for autologous donor area research. Multiple studies have conducted an in-depth analysis of the healing ability of the HPM at the cellular and molecular levels. In addition, the HPM has good maneuverability as a donor area for soft tissue grafts, and researchers have isolated various specific mesenchymal stem cells (MSCs) from HPM. Free soft tissue grafts obtained from the HPM have been widely used in the clinic and have played an essential role in dentistry, eyelid reconstruction, and the repair of other specific soft tissue defects. This article reviews the advantages of HPM as a donor area and its related mechanisms, classes of HPM-derived biomaterials, the current status of clinical applications, challenges, and future development directions.

A high-salt diet promotes hypertrophic scarring through TRPC3-mediated mitochondrial Ca2+ homeostasis dysfunction

Diet High in salt content have been associated with cardiovascular disease and chronic inflammation. We recently demonstrated that transient receptor potential canonical 3 (TRPC3) channels regulate myofibroblast transdifferentiation in hypertrophic scars. Here, we examined how high salt activation of TRPC3 participates in hypertrophic scarring during wound healing. In vitro, we confirmed that high salt increased the TRPC3 protein expression and the marker of myofibroblast alpha smooth muscle actin (α-SMA) in wild-type mice (WT) primary cultured dermal fibroblasts but not Trpc3-/- mice. Activation of TRPC3 by high salt elevated cytosolic Ca2+ influx and mitochondrial Ca2+ uptake in dermal fibroblasts in a TRPC3-dependent manner. High salt activation of TRPC3 enhanced mitochondrial respiratory dysfunction and excessive ROS production by inhibiting pyruvate dehydrogenase action, that activated ROS-triggered Ca2+ influx and the Rho kinase/MLC pathway in WT mice but not Trpc3-/- mice. In vivo, a persistent high-salt diet promoted myofibroblast transdifferentiation and collagen deposition in a TRPC3-dependent manner. Therefore, this study demonstrates that high salt enhances myofibroblast transdifferentiation and promotes hypertrophic scar formation through enhanced mitochondrial Ca2+ homeostasis, which activates the ROS-mediated pMLC/pMYPT1 pathway. TRPC3 deficiency antagonizes high salt diet-induced hypertrophic scarring. TRPC3 may be a novel target for hypertrophic scarring during wound healing.

Molecular hydrogen promotes wound healing by inducing early epidermal stem cell proliferation and extracellular matrix deposition

BACKGROUND

Despite progress in developing wound care strategies, there is currently no treatment that promotes the self-tissue repair capabilities. H₂ has been shown to effectively protect cells and tissues from oxidative and inflammatory damage. While comprehensive effects and how H₂ functions in wound healing remains unknown, especially for the link between H₂ and extracellular matrix (ECM) deposition and epidermal stem cells (EpSCs) activation.

METHODS

Here, we established a cutaneous aseptic wound model and applied a high concentration of H₂ (66% H₂) in a treatment chamber. Molecular mechanisms and the effects of healing were evaluated by gene functional enrichment analysis, digital spatial profiler analysis, blood perfusion/oxygen detection assay, in vitro tube formation assay, enzyme-linked immunosorbent assay, immunofluorescent staining, non-targeted metabonomic analysis, flow cytometry, transmission electron microscope, and live-cell imaging.

RESULTS

We revealed that a high concentration of H₂ (66% H₂) greatly increased the healing rate (3 times higher than the control group) on day 11 post-wounding. The effect was not dependent on O₂ or anti-reactive oxygen species functions. Histological and cellular experiments proved the fast re-epithelialization in the H₂ group. ECM components early (3 days post-wounding) deposition were found in the H₂ group of the proximal wound, especially for the dermal col-I, epidermal col-III, and dermis-epidermis-junction col-XVII. H₂ accelerated early autologous EpSCs proliferation (1-2 days in advance) and then differentiation into myoepithelial cells. These epidermal myoepithelial cells could further contribute to ECM deposition. Other beneficial outcomes include sustained moist healing, greater vascularization, less T-helper-1 and T-helper-17 cell-related systemic inflammation, and better tissue remodelling.

CONCLUSION

We have discovered a novel pattern of wound healing induced by molecular hydrogen treatment. This is the first time to reveal the direct link between H₂ and ECM deposition and EpSCs activation. These H₂-induced multiple advantages in healing may be related to the enhancement of cell viability in various cells and the maintenance of mitochondrial functions at a basic level in the biological processes of life.

LPS-pretreatment adipose-derived mesenchymal stromal cells promote wound healing in diabetic rats by improving angiogenesis

Mesenchymal stem cells (MSCs) play a key role in wound healing, and the advantages of pretreated MSCs in wound healing have previously been reported. In the present study, we investigated the impact of LPS pretreated human adipose-derived MSCs on skin wound healing in diabetic rats. We found that some improvements occurred through improving angiogenesis. Then, we scrutinized the impact of lipopolysaccharide (LPS) treatment on human adipose-derived MSCs in a high-glucose (HG) medium, as an in vitro diabetic model. In vivo findings revealed significant improvements in epithelialization and angiogenesis of diabetic wounds which received LPS pre-MSCs. Particularly, LPS pre-MSCs-treated diabetic wounds reached considerably higher percentages of wound closure. Also, the granulation tissue of these wounds had higher pronounced epithelialization and more vascularization compared with PBS-treated and MSCs-treated diabetic ones by CD31, VEGF, CD90, collagen 1, and collagen 3 immunostaining. Western-blots analyses indicated that LPS pre-MSCs led to the upregulation of vascular endothelial growth factor (VEGF) and DNMT1. In addition, significantly higher cell viability (proliferation/colonie), and elevated VEGF and DNMT1 protein expression were observed when MSCs were treated with LPS (10 ng/ml, 6 h) in HG culture media. Based on these findings, it is suggested that LPS pre-MSCs could promote wound repair and skin regeneration, in some major processes, via the improvement of cellular behaviors of MSCs in the diabetic microenvironment. The beneficial advantages of LPS treated with mesenchymal stem cells on wound healing may lead to establishing a novel approach as an alternative therapeutic procedure to cure chronic wounds in diabetic conditions.

The actin cytoskeleton: Morphological changes in pre- and fully developed lung cancer

Actin, a primary component of the cell cytoskeleton can have multiple isoforms, each of which can have specific properties uniquely suited for their purpose. These monomers are then bound together to form polymeric filaments utilizing adenosine triphosphate hydrolysis as a source of energy. Proteins, such as Arp2/3, VASP, formin, profilin, and cofilin, serve important roles in the polymerization process. These filaments can further be linked to form stress fibers by proteins called actin-binding proteins, such as α-actinin, myosin, fascin, filamin, zyxin, and epsin. These stress fibers are responsible for mechanotransduction, maintaining cell shape, cell motility, and intracellular cargo transport. Cancer metastasis, specifically epithelial mesenchymal transition (EMT), which is one of the key steps of the process, is accompanied by the formation of thick stress fibers through the Rho-associated protein kinase, MAPK/ERK, and Wnt pathways. Recently, with the advent of "field cancerization," pre-malignant cells have also been demonstrated to possess stress fibers and related cytoskeletal features. Analytical methods ranging from western blot and RNA-sequencing to cryo-EM and fluorescent imaging have been employed to understand the structure and dynamics of actin and related proteins including polymerization/depolymerization. More recent methods involve quantifying properties of the actin cytoskeleton from fluorescent images and utilizing them to study biological processes, such as EMT. These image analysis approaches exploit the fact that filaments have a unique structure (curvilinear) compared to the noise or other artifacts to separate them. Line segments are extracted from these filament images that have assigned lengths and orientations. Coupling such methods with statistical analysis has resulted in development of a new reporter for EMT in lung cancer cells as well as their drug responses.

Comparison of Wound Healing Effect of Skin Micrograft Impregnated into Two Kinds of Artificial Dermis in a Murine Wound Model

A micrograft (MG) suspension produced by the Rigenera protocol has been used to stimulate tissue regeneration. Recently, a combination therapy of an artificial dermis and skin MG has been used to promote angiogenesis and granulation tissue formation in the artificial dermis. There are no reports comparing the differences in MG impregnation efficiency between different artificial dermis products. Therefore, we compared the impregnation of skin MG in Pelnac Gplus and Integra.

Methods

Skin MG was prepared from the skin of C57BL/6JJcl mice using Rigeneracons and administered onto Pelnac Gplus and Integra sheets. The amount of MG suspension impregnated in Pelnac Gplus and Integra was evaluated. Pelnac Gplus and Integra sheets combined with MG were applied to murine defects, and wound area, neoepithelium length, granulation tissue formation, and newly formed capillaries were compared with the control groups on days 7 and 14.

Results

The weight percentage of the MG absorbed by Pelnac Gplus and Integra was 88.8% ± 3.5% and 28.2% ± 7.0%, respectively (P < 0.05). In the in vivo experiment, the area of newly formed granulation tissue and both the number and area of newly formed capillaries in the PelnacG + MG group were significantly larger than those in the control group at 14 days after implantation (P < 0.05).

Conclusions

Skin MG was successfully impregnated into Pelnac Gplus by simple administration but not into Integra. Administration of skin MG into the Pelnac Gplus promoted granulation formation and angiogenesis. Pelnac Gplus was more suitable than Integra in the combination therapy.

3D bioprinting and Rigenera® micrografting technology: A possible countermeasure for wound healing in spaceflight

Plant and animal life forms have progressively developed mechanisms for perceiving and responding to gravity on Earth, where homeostatic mechanisms require feedback. Lack of gravity, as in the International Space Station (ISS), induces acute intra-generational changes in the quality of life. These include reduced bone calcium levels and muscle tone, provoking skin deterioration. All these problems reduce the work efficiency and quality of life of humans not only during exposure to microgravity (µG) but also after returning to Earth. This article discusses forthcoming experiments required under gravity and µG conditions to ensure effective and successful medical treatments for astronauts during long-term space missions, where healthcare is difficult and not guaranteed.

Promotive effects of four herbal medicine ARCC on wound healing in mice and human

Background

Traditional Chinese medicine (TCM) had been extensively used in China for wound management and had shown great potential in wound treatment while its mechanism is still needed to be addressed.

Objective

The present study sought to investigate the therapuetic effect of the TCM ARCC on acute and chronic wounds.

Methods

Here, using the ultra‐low temperature preparation method, the mixed ultramicro powder prepared with Angelica (A), Angelica (R), Calcined Gypsum (C) and Caleramide (C) named as ARCC. The effects of ARCC on wound healing in adult and aged mice were comparatively evaluated through a full‐thickness skin defect model. In addition, we randomly selected 10 patients aged 55 to 70 years from a cohort of 500 patients with diabetic feet to assess their prognosis.

Results

As the results showed that the healing rate had delayed in aged mice compared to adult mice, while ARCC prominently augmented the healing process in aged mice. Moreover, ARCC treatment wounds in aged mice showed accelerated re‐epithelization, enhanced granulation tissue formation, and increased vascularization, which was similar to that of adult mice. Furthermore, ARCC also achieved therapeutic effects in diabetic foot patients, accelerating wound healing. The results found that foot ulcers improved significantly 7 days after the ARCC administration, and 80% of patients were healed within 1 month.

Discussion

In the present study, ARCC was found to have therapeutic effects on both acute and chronic wounds in animal models. ARCC also demonstrated therapeutic effects in diabetic feet, which promoted wound healing, prevented wound infection, and avoided the risk of further surgery or amputation. All these evidences suggested ARCC was a promising approach for wound treatment.

Conclusions

ARCC might be recommended as a promising therapeutic medication in diabetic and chronic refractory wounds.

A Histological Evaluation of Artificial Dermal Scaffold Used in Micrograft Treatment: A Case Study of Micrograft and NPWT Performed on a Postoperative Ulcer Formation after Tumor Resection

Background and Objectives: Wound healing (WH) is a complex natural process: the achieving of a proper WH with standard therapies sometimes is not fulfilled and it is often observed in aged and diabetic patients, leading to intractable ulcers. In recent years, autologous micrograft (AMG) therapies have become a new, effective, and affordable wound care strategy among both researchers and clinicians. In this study, a 72-year-old female patient underwent a combination of treatments using micrograft and negative pressure wound therapy (NPWT) on a postoperative skin ulcer after a benign tumor resection on the back with the aim to present an innovative method to treat skin ulceration using AMG combined with an artificial dermal scaffold and NPWT. Materials and Methods: A section of the artificial dermal scaffold, infused with micrografts, was sampled prior to transplant, and sections were collected postoperatively on days 3 and 7. Hematoxylin-eosin (HE) and immunohistochemical stains were employed for the evaluation of Cytokeratin AE1/AE3, desmin, and Factor VIII. Additionally, on postoperative day 3, NPWT dressing was evaluated using HE stains, as well. The resulting HE and immunostaining analysis revealed red blood cells and tissue fragments within the collagen layers of the artificial dermis prior to transplant. On postoperative day 3, collagen layers of the artificial dermis revealed red blood cells and neutrophils based on HE stains, and scattering of cytokeratin AE1/AE3-positive cells were detected by immunostaining. The HE stains on postoperative day 7 showed more red blood cells and neutrophils within the collagen layers of the artificial dermis than on day 3, an increase in cytokeratin AE1/AE3-positive cells, and tissue stained positively with desmin and Factor VIII. Results: Results suggest that the effects of both micrografts and migratory cells have likely accelerated the wound healing process. Furthermore, the NPWT dressing on day 3 showed almost no cells within the dressing. This indicated that restarting NPWT therapy immediately after micrograft transplant did not draw out cells within the scaffold. Conclusions: Micrograft treatment and NPWT may serve to be a useful combination therapy for complex processes of wound healing.

Precise Diabetic Wound Therapy: PLS Nanospheres Eliminate Senescent Cells via DPP4 Targeting and PARP1 Activation

Diabetic ulcers, a difficult problem faced by clinicians, are strongly associated with an increase in cellular senescence. Few empirical studies have focused on exploring a targeted strategy to cure diabetic wounds by eliminating senescent fibroblasts (SFs) and reducing side effects. In this study, poly-l-lysine/sodium alginate (PLS) is modified with talabostat (PT100) and encapsulates a PARP1 plasmid (PARP1@PLS-PT100) for delivery to target the dipeptidyl peptidase 4 (DPP4) receptor and eliminate SFs. PARP1@PLS-PT100 releases encapsulated plasmids, displaying high selectivity for SFs over normal fibroblasts by targeting the DPP4 receptor, decreasing senescence-associated secretory phenotypes (SASPs), and stimulating the secretion of anti-inflammatory factors. Furthermore, the increased apoptosis of SFs and the disappearance of cellular senescence alleviates SASPs, accelerates re-epithelialization and collagen deposition, and significantly induces macrophage M2 polarization, which mediates tissue repair and the inflammatory response. This innovative strategy has revealed the previously undefined role of PARP1@PLS-PT100 in promoting diabetic wound healing, suggesting its therapeutic potential in refractory wound repair.

A novel mouse wound model for scar tissue formation in abdominal muscle wall

Hypertrophic scars found on the human body rarely develop in experimental animals, possibly due to their looser skin structure. This makes it difficult to understand the genesis of scar lesions. Therefore, appropriate animal models are urgently needed. In this study, we established a novel experimental model of a scar-forming wound by resecting a small portion of the abdominal muscle wall on the lower center of the abdomen in C57BL/6N mice, which are exposed to contractive forces by the surrounding muscle tissue. As a low-tension control, a back skin excision model was used with a splint fixed onto the excised skin edge, and granulation tissue formed on the muscle fascia supported by the back skeleton. One week after the resection, initial healing reactions, such as fibroblast proliferation, occurred in both models. However, after 21 days, lesions with collagen-rich granulation tissues, which were also accompanied by multiple nodular/spherical-like structures, developed only in the abdominal wall model. These lesions were analogous to scar lesions in humans. Therefore, the animal model developed in this study is unique in that fibrous scar tissues form under physiological conditions without using any artificial factors and is valuable for studying the pathogenesis and preclinical treatment of scar lesions.

Extracellular Vesicles From a Three-Dimensional Culture of Perivascular Cells Accelerate Skin Wound Healing in a Rat

BACKGROUND

Soluble proteins and extracellular vesicles (EVs) are crucial wound repair mediators in cell-based therapy. Previous studies reported that EVs of perivascular cells stimulated migration and proliferation of cell types involved in the dermatological wound healing process. However, these studies only show effects of EVs from perivascular cells (PVCs) for in vitro models.

METHODS

EVs were collected from 3D-cultured PVC (PVC-3D-EV) and compared with EVs from 2D-culture PVC (PVC-2D-EV) to investigate effects on wound contraction, angiogenesis, activation of myofibroblast, and collagen deposition.

RESULTS

PVC-3D-EV was significantly improved in terms of wound contraction compared with PVC-2D-EV and the control. Activation of myofibroblast and collagen deposition in a rat skin wound model was significantly stimulated by PVC-3D-EV. In addition, angiogenesis and vascular endothelial growth factor expression were also highly stimulated by PVC-3D-EV. These results suggest that PVC-3D-EV was regulated in granulation tissue formation, angiogenesis, and wound contraction in healing of a rat skin wound. These results indicate a pivotal role of PVC-3D-EV in wound healing through multiple mechanisms.

CONCLUSIONS

3D-culture using a polystyrene scaffold is demonstrated to be a better system for providing better physiological conditions than the 2D-culture system, and EVs from 3D-cultured PVC could be a promising option for healing skin wound.

NO LEVEL ASSIGNED

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Beneficial effect on rapid skin wound healing through carboxylic acid-treated chicken eggshell membrane

At the initial stage of wound healing, growth factors stimulate tissue regeneration by interacting with the extracellular matrix (ECM), leading to rapid wound repair and structural support. Chicken eggshell membrane (ESM) is a low-cost and highly functional ECM biomaterial for tissue regeneration. However, natural ESM has limitations for tissue engineering purposes because it is difficult to control the size, shape, and biocompatibility of the surfaces. To overcome this, blends of synthetic materials and natural ESMs, such as soluble eggshell membrane protein, are combined for biomaterial applications. Unfortunately, it is difficult to pattern fibrous structure. Here, we modified the natural chicken ESM through weak acid treatment to promote wound healing and skin regeneration without loss of fibrous structure. Treatment of citric acid and acetic acid reacted the amine or amide group with carboxyl groups (R-COOH) and achieved hydrophilicity for adherence of proliferating regenerative cells. Our in vitro study revealed that the modified ESM scaffolds significantly promoted human dermal fibroblasts adhesion, viability, proliferation, and cytokine secretion, compared with natural ESM. In addition, the modified ESM accelerated skin regeneration and enhanced the wound healing process even at early stages in an in vivo rat wound model. Collectively, the modified ESM performed best for promoting skin regeneration, cytokine secretion, epidermal cell proliferation, and controlling the inflammatory response both in vitro and in vivo.

Nanodefensin-encased hydrogel with dual bactericidal and pro-regenerative functions for advanced wound therapy

Background: Host defense peptides (HDPs) have emerged as a novel therapeutic paradigm for wound management; however, their clinical applications remain a challenge owing to their poor pharmacological properties and lack of suitable pharmaceutical formulations. Nanodefensin (ND), a nanoengineered human α-defensin 5 (HD5), has shown improved pharmacological properties relative to the parent compound. In this study, we engineered a nanodefensin-encased hydrogel (NDEFgel), investigated the effects of NDEFgel on wound healing, and elucidated underlying mechanisms. Method: ND was chemically synthesized and tested functions by in vitro antimicrobial and scratch assays and western blotting. Different NDEFgels were evaluated by in vitro characterizations including degradation, drug release and antimicrobial activity. In full-thickness excisional murine models, the optimal NDEFgel was directly applied onto wound sites, and the efficacy was assessed. Moreover, the underlying mechanisms of pro-regenerative effect developed by NDEFgel were also explored. Results: Apart from bactericidal effects, ND modulated fibroblast behaviors by promoting migration and differentiation. Among the tested hydrogels, the Pluronic F127 (Plu) hydrogel represented the most desirable carrier for ND delivery owing to its favorable controlled release and compatibility with ND. Local treatment of NDEFgel on the wound bed resulted in accelerated wound regeneration and attenuated bacterial burden. We further demonstrated that NDEFgel therapy significantly upregulated genes related to collagen deposition and fibroblasts, and increased the expression of myofibroblasts and Rac1. We therefore found that Rac1 is a critical factor in the ND-induced modulation of fibroblast behaviors in vitro through a Rac1-dependent cytoskeletal rearrangement. Conclusion: Our results indicate that NDEFgel may be a promising dual-action therapeutic option for advanced wound management in the future.

Autologous micrografts from the palatal mucosa for bone regeneration in calvarial defects in rats: a radiological and histological analysis

BACKGROUND

The application of dental implants is often restricted by bone volume. In such cases, bone grafts are required, although bone graft materials have some disadvantages. Therefore, other effective approaches are needed. Our previous study showed that the autologous micrograft, a dissociated cell suspension made out of palatal connective tissue grafts, promoted bone-marrow cell proliferation and differentiation under osteogenic conditions. In this study, we aimed to evaluate the effects of dissociated soft-tissue suspensions relevant to bone regeneration in animal model.

MATERIAL AND METHODS

Twelve-week-old male Wistar rats were used in the study. Defects were created in rat calvaria, and were filled with hydrogel containing either dissociated soft-tissue suspension (test) or sucrose (control). The new bone formation was evaluated at 1 and 2 weeks after surgery (n = 16) by radiological and histological analysis.

RESULTS

The conducted radiological analysis showed that the new bone volume was significantly greater in the dissociated soft-tissue suspension group. This finding was further confirmed by the conducted histological analysis.

CONCLUSIONS

The dissociated mucosa tissue suspension enhanced bone regeneration in vivo; thus, it is a promising potential method to aid the successful application for bone augmentation in the implant practice.

Autologous micrografts and methotrexate in plantar erosive lichen planus: healing and pain control. A case report

Erosive lichen planus is an uncommon variant of lichen planus. We report a case of longstanding and refractory plantar ELPs causing disabling and opiate-resistant pain treated with ‘classic’ meshed skin graft combined with Rigenera^® micrografts. After approximately 9 months follow-up, no clinical recurrence or pain were observed. Erosive lichen planus (ELP) is an uncommon variant of lichen planus, involving oral cavity and genitalia and, less often plantar areas, where it usually presents with chronic erosions of the soles, along with intense, disabling pain and progressive loss of toenails. An abnormal immune cellular response (CD8+ lymphocytes and macrophages) and the consequent altered production of multiple mediators (interleukin-12, interferon-γ, tumor necrosis factor-α, RANTES and MMP-9), seem to play a crucial role in the pathogenesis, although the etiology remains uncertain. From a histological point of view, ELP shows keratinocyte apoptosis, intense inflammatory response and basal epithelial keratinocytes TNF-α overexpression. Several therapies have been proposed, with variable and controversial results. While topical corticosteroids and topical calcineurin inhibitors are the treatments of choice for localized forms, short pulses of systemic glucocorticoids, phototherapy, and systemic immunosuppressants are recommended for generalized cases. Surgery has been reported as a possible therapeutic option in refractory and stable cases with localized lesions, either alone or with cyclosporine. Herein, we report a case of longstanding and refractory plantar ELPS causing disabling and opiate-resistant pain treated with ‘classic’ meshed skin graft combined with Rigenera® micrografts.

A Novel Autologous Micrografts Technology in Combination with Negative Pressure Wound Therapy (NPWT) for Quick Granulation Tissue Formation in Chronic/Refractory Ulcer

Negative pressure wound therapy (NPWT) has been commonly used over the years for a wide range of chronic/refractory lesions. Alternatively, autologous micrografting technology is recently becoming a powerful modality for initiating wound healing. The case presented is of a patient with a lower leg ulcer that had responded poorly to NPWT alone for three weeks. Consequently, the patient was put on a combination therapy of NPWT and micrografting. After injection of a dermal tissue micrografts suspension into the entire wound bed, NPWT was performed successively for two weeks, resulting in fresh granulation tissue formation. Thereafter, the autologous skin graft was taken well. This case study indicates that for a chronic/refractory ulcer patient with poor NPWT outcome, combination therapy using micrografting treatment and NPWT could rapidly initiate and enhance granulation tissue formation, creating a favorable bedding for subsequent skin grafting.

Novel application of autologous micrografts in a collagen-glycosaminoglycan scaffold for diabetic wound healing

BACKGROUND

Therapeutic strategies that successfully combine two techniques-autologous micrografting and biodegradable scaffolds-offer great potential for improved wound repair and decreased scarring. In this study we evaluate the efficacy of a novel modification of a collagen-glycosaminoglycan scaffold with autologous micrografts using a murine dorsal wound model.

METHODS

db/db mice underwent dorsal wound excision and were treated with a collagen-glycosaminoglycan scaffold (CGS), a modified collagen-glycosaminoglycan scaffold (CGS+MG) or simple occlusive dressing (Blank). The modified scaffold was created by harvesting full thickness micrografts and transplanting these into the collagen-glycosaminoglycan membrane. Parameters of wound healing, including cellular proliferation, collagen deposition, keratinocyte migration, and angiogenesis were assessed.

RESULTS

The group treated with the micrograft-modified scaffold healed at a faster rate, showed greater cellular proliferation, collagen deposition, and keratinocyte migration with higher density and greater maturity of microvessels. The grafts remained viable within the scaffold with no evidence of rejection. Keratinocytes were shown to migrate from the wound border and from the micrograft edges towards the center of the wound, while cellular proliferation was present both at the wound border and wound bed.

CONCLUSION

We report successful treatment of diabetic wounds with a novel collagen-glycosaminoglycan scaffold modified with full-thickness automicrografts. Differences in cellular migration and proliferation offer maiden evidence on the mechanisms of wound healing. Clinically, the successful scaffold engraftment, micrograft viability and improved wound healing offer promising results for the development of a new therapeutic modality for wound repair.

Evaluation of Bone Regeneration in Rat Calvaria Using Bone Autologous Micrografts and Xenografts: Histological and Histomorphometric Analysis

The aim of this study was to investigate the effect of the use of autologous micrografts obtained by the Rigenera® Micrografting Technology and xenograft on critical size defects created in the calvaria of rats. Forty-eight rats were randomly divided into four groups for each of the two evaluation times (15 and 30 days) (n = 6). After general anesthesia, a 5-mm diameter bone defect was created in the calvaria of each animal. Each defect was filled with the following materials: blood clot, autologous bone graft, xenograft, and xenograft associated with autologous micrografts. Histomorphometric and histological analysis showed that the group that have received the Rigenera® processed autologous micrografts combined with the xenograft and the group that received autologous bone graft resulted in greater bone formation in both time points when compared with the use of the xenograft alone and blood clot.

Effects of autologous micrografts on stable bilateral vitiligo: A focus on hand lesions

Vitiligo is an autoimmune skin disorder characterized by depigmented patches of the skin associated with, among several factors, dysregulation and death of melanocytes. Currently, the treatment of vitiligo is based both on the arrest of the progression of active disease and on the stimulation of the skin repigmentation. The aim of this study was to assess the effects of autologous micrografts and narrowband ultraviolet B (NBUVB) phototherapy for skin repigmentation of patients with bilateral stable vitiligo. Autologous micrografts are derived from mechanical disaggregation of small pieces of the patient's own skin, while phototherapy is a strategy treatment already used. Twenty patients with stable bilateral vitiligo were treated, showing a mean percentage rate of 59.1% at baseline. Combined treatment by autologous micrografts and NBUVB was performed only on the lesions of the hands, and the clinical follow up was performed after 3 and 6 months by photographs taken under Wood's light. After 6 months, we classed 100% of patients as responders. We also reported a mean of repigmentation rate of 36.7% after 3 months and 64.6% after 6 months of treatment. In particular, six of the 20 patients reached a marked repigmentation rate (75-100%), four moderate (51-75%) and 10 mild (26-50%). No adverse effects were observed and no drugs were administrated as co-adjuvant therapy. These results are suggestive of a potential wide use of autologous micrografts associated with NBUVB phototherapy for the treatment of stable vitiligo.

A New Animal Model for Pathological Subcutaneous Fibrosis: Surgical Technique and in vitro Analysis

Fibrosis is a condition that affects the connective tissue in an organ or tissue in the restorative or responsive phase as a result of injury. The consequences of excessive fibrotic tissue growth may lead to various physiological complications of deformity and impairment due to hypertrophic scars, keloids, and tendon adhesion without understating the psychological impact on the patient. However, no method accurately quantifies the rate and pattern of subcutaneous induced hypertrophic fibrosis. We, therefore, devised a rodent excisional model to evaluate the extent of fibrosis with talc. Tissue specimens were set on formalin, and paraffin sections for histological, immunohistochemical, and molecular analysis talc was used to induce the fibroproliferative mechanism typical of hypertrophic scars. This pathway is relevant to the activation of inflammatory and fibrotic agents to stimulate human hypertrophic scarring. This model reproduces morpho-functional features of human hypertrophic scars to investigate scar formation and assess potential anti-scarring therapies.

Acceleration of Skin Wound-Healing Reactions by Autologous Micrograft Tissue Suspension

Background and objectives: Skin grafting is a method usually used in reconstructive surgery to accelerate skin regeneration. This method results frequently in unexpected scar formations. We previously showed that cutaneous wound-healing in normal mice is accelerated by a micrograft (MG) technique. Presently, clinical trials have been performed utilizing this technology; however, the driving mechanisms behind the beneficial effects of this approach remain unclear. In the present study, we focused on five major tissue reactions in wound-healing, namely, regeneration, migration, granulation, neovascularization and contraction. Methods: Morphometrical analysis was performed using tissue samples from the dorsal wounds of mice. Granulation tissue formation, neovascularization and epithelial healing were examined. Results: The wound area correlated well with granulation sizes and neovascularization densities in the granulation tissue. Vascular distribution analysis in the granulation tissue indicated that neovessels extended and reached the subepidermal area in the MG group but was only halfway developed in the control group. Moreover, epithelialization with regeneration and migration was augmented by MG. Myofibroblast is a known machinery for wound contraction that uses α-smooth muscle actin filaments. Their distribution in the granulation tissue was primarily found beneath the regenerated epithelium and was significantly progressed in the MG group. Conclusions: These findings indicated that MG accelerated a series of wound-healing reactions and could be useful for treating intractable wounds in clinical situations.

In Vitro Characterization of Adipose Stem Cells Non-Enzymatically Extracted from the Thigh and Abdomen

Autologous fat grafting is a surgical technique in which adipose tissue is transferred from one area of the body to another, in order to reconstruct or regenerate damaged or injured tissues. Before reinjection, adipose tissue needs to be purified from blood and cellular debris to avoid inflammation and preserve the graft viability. To perform this purification, different enzymatic and mechanical methods can be used. In this study, we characterized in vitro the product of a closed automatic device based on mechanical disaggregation, named Rigenera^®, focusing on two sites of adipose tissue harvesting. At first, we optimized the Rigenera^® operating timing, demonstrating that 60 s of treatment allows a higher cellular yield, in terms of the cell number and growth rate. This result optimizes the mechanical disaggregation and it can increase the clinical efficiency of the final product. When comparing the extracted adipose samples from the thigh and abdomen, our results showed that the thigh provides a higher number of mesenchymal-like cells, with a faster replication rate and a higher ability to form colonies. We can conclude that by collecting adipose tissue from the thigh and treating it with the Rigenera^® device for 60 s, it is possible to obtain the most efficient product.

Electrospun Fibers and Sorbents as a Possible Basis for Effective Composite Wound Dressings

Skin burns and ulcers are considered hard-to-heal wounds due to their high infection risk. For this reason, designing new options for wound dressings is a growing need. The objective of this work is to investigate the properties of poly (ε-caprolactone)/poly (vinyl-pyrrolidone) (PCL/PVP) microfibers produced via electrospinning along with sorbents loaded with Argovit™ silver nanoparticles (Ag-Si/Al2O3) as constituent components for composite wound dressings. The physicochemical properties of the fibers and sorbents were characterized using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and inductively coupled plasma optical emission spectroscopy (ICP-OES). The mechanical properties of the fibers were also evaluated. The results of this work showed that the tested fibrous scaffolds have melting temperatures suitable for wound dressings design (58-60 °C). In addition, they demonstrated to be stable even after seven days in physiological solution, showing no macroscopic damage due to PVP release at the microscopic scale. Pelletized sorbents with the higher particle size demonstrated to have the best water uptake capabilities. Both, fibers and sorbents showed antimicrobial activity against Gram-negative bacteria Pseudomona aeruginosa and Escherichia coli, Gram-positive Staphylococcus aureus and the fungus Candida albicans. The best physicochemical properties were obtained with a scaffold produced with a PCL/PVP ratio of 85:15, this polymeric scaffold demonstrated the most antimicrobial activity without affecting the cell viability of human fibroblast. Pelletized Ag/Si-Al2O3-3 sorbent possessed the best water uptake capability and the higher antimicrobial activity, over time between all the sorbents tested. The combination of PCL/PVP 85:15 microfibers with the chosen Ag/Si-Al2O3-3 sorbent will be used in the following work for creation of wound dressings possessing exudate retention, biocompatibility and antimicrobial activity.

Noncontact Phased-Array Ultrasound Facilitates Acute Wound Healing in Mice

Supplemental Digital Content is available in the text.

Background:

The authors developed a noncontact low-frequency ultrasound device that delivers high-intensity mechanical force based on phased-array technology. It may aid wound healing because it is likely to be associated with lower risks of infection and heat-induced pain compared with conventional ultrasound methods. The authors hypothesized that the microdeformation it induces accelerates wound epithelialization. Its effects on key wound-healing processes (angiogenesis, collagen accumulation, and angiogenesis-related gene transcription) were also examined.

Methods:

Immediately after wounding, bilateral acute wounds in C57BL/6J mice were noncontact low-frequency ultrasound– and sham-stimulated for 1 hour/day for 3 consecutive days (10 Hz/90.6 Pa). Wound closure (epithelialization) was recorded every 2 days as the percentage change in wound area relative to baseline. Wound tissue was procured on days 2, 5, 7, and 14 (five to six per time point) and subjected to histopathology with hematoxylin and eosin and Masson trichrome staining, CD31 immunohistochemistry, and quantitative polymerase-chain reaction analysis.

Results:

Compared to sham-treated wounds, ultrasound/phased-array–treated wounds exhibited significantly accelerated epithelialization (65 ± 27 percent versus 30 ± 33 percent closure), angiogenesis (4.6 ± 1.7 percent versus 2.2 ± 1.0 percent CD31⁺ area), and collagen deposition (44 ± 14 percent versus 28 ± 13 percent collagen density) on days 5, 2, and 5, respectively (all p < 0.05). The expression of Notch ligand delta-like 1 protein (Dll1) and Notch1, which participate in angiogenesis, was transiently enhanced by treatment on days 2 and 5, respectively.

Conclusions:

The authors’ noncontact low-frequency ultrasound phased-array device improved the wound-healing rate. It was associated with increased early neovascularization that was followed by high levels of collagen-matrix production and epithelialization. The device may expand the mechanotherapeutic proangiogenesis field, thereby helping stimulate a revolution in infected wound care.

Activator Protein-1 Transcriptional Activity Drives Soluble Micrograft-Mediated Cell Migration and Promotes the Matrix Remodeling Machinery

Impaired wound healing and tissue regeneration have severe consequences on the patient's quality of life. Micrograft therapies are emerging as promising and affordable alternatives to improve skin regeneration by enhancing the endogenous wound repair processes. However, the molecular mechanisms underpinning the beneficial effects of the micrograft treatments remain largely unknown. In this study, we identified the active protein-1 (AP-1) member Fos-related antigen-1 (Fra-1) to play a central role in the extracellular signal-regulated kinase- (ERK-) mediated enhanced cell migratory capacity of soluble micrograft-treated mouse adult fibroblasts and in the human keratinocyte cell model. Accordingly, we show that increased micrograft-dependent in vitro cell migration and matrix metalloprotease activity is abolished upon inhibition of AP-1. Furthermore, soluble micrograft treatment leads to increased expression and posttranslational phosphorylation of Fra-1 and c-Jun, resulting in the upregulation of wound healing-associated genes mainly involved in the regulation of cell migration. Collectively, our work provides insights into the molecular mechanisms behind the cell-free micrograft treatment, which might contribute to future advances in wound repair therapies.

A Multicentre Study: The Use of Micrografts in the Reconstruction of Full-Thickness Posttraumatic Skin Defects of the Limbs-A Whole Innovative Concept in Regenerative Surgery

The skin graft is a surgical technique commonly used in the reconstructive surgery of the limbs, in order to repair skin loss, as well as to repair the donor area of the flaps and cover the dermal substitutes after engraftment. The unavoidable side effect of this technique consists of unaesthetic scars. In order to achieve the healing of posttraumatic ulcers by means of tissue regeneration and to avoid excessive scarring, a new innovative technology based on the application of autologous micrografts, obtained by Rigenera technology, was reported. This technology was able to induce tissue repair by highly viable skin micrografts of 80 micron size achieved by a mechanical disaggregation method. The specific cell population of these micrografts includes progenitor cells, which in association with the fragment of the Extracellular Matrix (ECM) and growth factors derived by patients' own tissue initiate biological processes of regeneration enhancing the wound healing process. We have used this technique in 70 cases of traumatic wounds of the lower and upper limbs, characterized by extensive loss of skin substance and soft tissue. In all cases, we have applied the Rigenera protocol using skin micrografts, achieving in 69 cases the complete healing of wounds in a period between 35 and 84 days. For each patient, the reconstructive outcome was evaluated weekly to assess the efficacy of this technique and any arising complication. A visual analogue scale (VAS) was administered to assess the amount of pain felt after the micrografts' application, whereas we evaluated the scars according to the Vancouver scale and the wound prognosis according to Wound Bed Score. We have thus been able to demonstrate that Rigenera procedure is very effective in stimulating skin regeneration, while reducing the outcome scar.

Autologous micrograft accelerates endogenous wound healing response through ERK-induced cell migration

Defective cell migration causes delayed wound healing (WH) and chronic skin lesions. Autologous micrograft (AMG) therapies have recently emerged as a new effective and affordable treatment able to improve wound healing capacity. However, the precise molecular mechanism through which AMG exhibits its beneficial effects remains unrevealed. Herein we show that AMG improves skin re-epithelialization by accelerating the migration of fibroblasts and keratinocytes. More specifically, AMG-treated wounds showed improvement of indispensable events associated with successful wound healing such as granulation tissue formation, organized collagen content, and newly formed blood vessels. We demonstrate that AMG is enriched with a pool of WH-associated growth factors that may provide the starting signal for a faster endogenous wound healing response. This work links the increased cell migration rate to the activation of the extracellular signal-regulated kinase (ERK) signaling pathway, which is followed by an increase in matrix metalloproteinase expression and their extracellular enzymatic activity. Overall we reveal the AMG-mediated wound healing transcriptional signature and shed light on the AMG molecular mechanism supporting its potential to trigger a highly improved wound healing process. In this way, we present a framework for future improvements in AMG therapy for skin tissue regeneration applications.

Progress report for intractable ulcer and osteomyelitis cases using autologous micrografts

Intractable ulcers often occur following primary diseases and have a significant impact on the quality of life of affected subjects. The medical treatments now available include compression and continuous debridement or additional interventions such as advanced wound dressings, local or systemic antibiotics with a mild benefit for the patients in the long term. In this report, we describe the use of autologous micrografts obtained by Rigenera^® procedure in the management of two cases of intractable ulcers showing good outcomes for both patients approximately after 30 days from intervention. In the first case, a 74-year-old male with a diagnosis of Fournier's gangrene who underwent several interventions showed a rapid wound epithelization after micrografts application. In the second case, a 63-year-old male affected by a left hallux ulcer with a diagnosis of chronic osteomyelitis also showed a gradual reduction in the ulcer approximately after 1 month from micrografts application.

Variation in Expression of Inflammation-Related Signaling Molecules with Profibrotic and Antifibrotic Effects in Cutaneous and Oral Mucosa Scars

Wound healing is a complex biologic process evolving in three phases: inflammation, proliferation, and tissue remodeling controlled by numerous growth factors and cytokines. Oral mucosa wounds heal with significantly less important scars with less numerous macrophages and mast cells and more numerous myofibroblasts than cutaneous counterparts. We analyzed 32 cutaneous and 32 oral mucosa scars for TGFbeta1, TGFbeta2, TGFbeta3, TNFalpha, PDGF BB and FGF1 expression in mesenchymal cells, endothelial cells, macrophages, and multinucleated giant cells. We identified differences in the expression of profibrotic and antifibrotic factors in oral mucosa and skin scars; TGFbeta2 was positive in cutaneous multinucleated giant cells, TNFalpha was positive in cutaneous macrophages, and both were negative in oral mucosa while TGFbeta3 was positive in oral macrophages and mostly negative in cutaneous ones. PDGF BB and FGF1 were positive in oral endothelial cells and oral macrophages and negative in macrophages with opposite positivity pattern in cutaneous scars. Based on these findings, macrophage seems to be the key player in modulating pro- and antifibrotic processes in wound regeneration.