Clinical applications of acellular dermal matrices: A review

Bioactivity and in vitro immunological studies of xenogeneic decellularized extracellular matrix scaffolds for implantable applications

Decellularized scaffolds retain the main bioactive substances of the extracellular matrix, which can better promote cell proliferation and matrix reconstruction at the defect site, and have great potential for morphological and functional restoration in patients with tissue defects. Due to the safety of the material source of allogeneic decellularized scaffolds, there is a great limitation in their clinical application, so the preparation and evaluation of xenodermal acellular scaffolds have attracted much attention. In terms of skin tissue structure and function, porcine skin has a high degree of similarity to human skin and has the advantages of sufficient quantity and no ethical issues. However, there is a risk of immune rejection after xenodermal acellular scaffold transplantation. To address the above problems, this paper focuses on porcine dermal decellularized scaffolds prepared using two common decellularization preparation methods and compares the decellularization efficiency, retention of active components of the extracellular matrix, structural characterization of the decellularized scaffolds, and the effect of porcine dermal decellularized scaffolds on mouse Raw264.7 macrophages, so as to make a functional evaluation of the active components and immune effects of porcine dermal decellularized scaffolds, and to provide a reference for filling trauma-induced defects in humans.

Biomedical application of materials for external auditory canal: History, challenges, and clinical prospects

Biomaterials play an integral role in treatment of external auditory canal (EAC) diseases. Regarding the special anatomic structure and physiological characteristics of EAC, careful selection of applicable biomaterials was essential step towards effective management of EAC conditions. The bioactive materials can provide reasonable biocompatibility, reduce risk of host pro-inflammatory response and immune rejection, and promote the healing process. In therapeutic procedure, biomaterials were employed for covering or packing the wound, protection of the damaged tissue, and maintaining of normal structures and functions of the EAC. Therefore, understanding and application of biomaterials was key to obtaining great rehabilitation in therapy of EAC diseases. In clinical practice, biomaterials were recognized as an important part in the treatment of different EAC diseases. The choice of biomaterials was distinct according to the requirements of various diseases. As a result, awareness of property regarding different biomaterials was fundamental for appropriate selection of therapeutic substances in different EAC diseases. In this review, we firstly introduced the characteristics of EAC structures and physiology, and EAC pathologies were summarized secondarily. From the viewpoint of biomaterials, the different materials applied to individual diseases were outlined in categories. Besides, the underlying future of therapeutic EAC biomaterials was discussed.

Guillotine Transmetatarsal Amputations With Staged Closure Promote Early Ambulation and Limb Salvage in Patients With Advanced Chronic Limb-Threatening Ischemia

PURPOSE

Transmetatarsal amputation (TMA) with primary closure has long been an option for limb salvage in patients with advanced chronic limb-threatening ischemia (CLTI) with extensive tissue loss of the forefoot. However, TMA healing and closure techniques are challenging, specifically in high-risk patients. Guillotine transmetatarsal amputations (gTMA) with staged closure may provide an alternative treatment in this population. We report long-term outcomes of such technique.

MATERIALS AND METHODS

A single-center retrospective cohort study of CLTI patients undergoing gTMA between 2017 and 2020 was performed. Limb salvage, wound healing, and survival rates were quantified using Kaplan-Meier (KM) analysis. Multivariate regression was used to identify the effect of patient characteristics on the outcomes.

RESULTS

Forty-four gTMA procedures were reviewed. Median follow-up was 381 (interquartile range [IQR], 212-539.75) days. After gTMA, 87.8% (n=36) of the patients were able to ambulate after a median interval of 2 (IQR, 1-3) days. Eventual coverage was achieved in a personalized and staged approach by using a combination of skin substitutes (88.6%, n=39) ± split thickness skin grafts (STSG, 61.4%, n=27). KM estimates for limb salvage, wound healing, and survival were 84.1%, 54.5%, and 88.6% at 1 year and 81.8%, 63.8%, and 84.1% at 2 years. Wound healing was significantly associated with STSG application (p=0.002, OR=16.5, 95% CI 2.87-94.81).

CONCLUSION

gTMA resulted in high limb salvage rates during long-term follow-up in CLTI patients. Adjunctive STSG placement may enhance wound healing at the gTMA site, thus leading to expedited wound closure. Surgeons may consider gTMA as an alternative to reduce limb loss in CLTI patients at high risk of major amputation.

CLINICAL IMPACT

Currently, the clinical presentation of CLTI is becoming more complex to deal with due to the increasing comorbidities as the society becomes older. The data shown in this article means for clinicians that when facing diffused forefoot gangrene and extensive tissue loss, limb preservation could still be considered instead of major amputation. Guillotine transmetatarsal amputations in the setting of an aggressive multidisciplinary group, can be healed by the responsibly utilization of dermal substitutes and skin grafts leading to the preservation of the extremity, allowing mobility, avoiding of sarcopenia, and decreasing frailty. This will equate to maintenance of independent living and preservation of lifespan.

NovoSorb® Biodegradable Temporizing Matrix: a novel approach for treatment of extremity avulsion injuries in children

PURPOSE

In pediatric population, large soft tissue defects occur in avulsion injuries. In addition to the challenges of primary surgical therapy, elasticity, appearance and function of the scar in children are of crucial importance, especially in the context of body growth. So far various flaps, plasties, skin grafts and dermal substitutes have become established, although infections and skin shrinkage remain challenging. In 2020, a new skin substitute material-NovoSorb® Biodegradable Temporizing Matrix (BTM)-was introduced in Europe for temporary wound closure and tissue regeneration. The aim of this study was to evaluate the value of BTM in pediatric patients.

METHODS

The study included all children treated with BTM after traumatic soft tissue defects following limb avulsion injuries between June 2021 and June 2023 at a university hospital.

RESULTS

7 patients with limb avulsion injuries were treated with BTM, 4 boys, 3 girls. Mean age was 6.5 years (2-11 years) at the time of BTM placement. 4/7 had concomitant fractures. BTM was used successfully in all cases, infection did not occur, skin shrinkage was seen in one case. Split thickness skin graft (STSG) after BTM application was performed in average after 33 days (26 to 39 days). Limitations of this study were highlighted.

CONCLUSION

BTM is a promising alternative for reconstruction of complex trauma extremity wounds in children following avulsion injuries, even in cases of concomitant bone injuries. Interpretation may be limited by sample size.

Local Therapy and Reconstruction in Penile Cancer: A Review

Local therapy for penile cancer provides robust survival and can preserve the penis functionally and cosmetically. Interventions must target the appropriate clinical stage. We reviewed studies regarding the primary therapy in penile cancer, from topical therapy to radical penectomy, and reconstructive techniques. Topical therapy (5-FU or Imiquimod) provides a robust oncologic response in patients with Ta or Tis disease. Multiple laser therapies are available for localized patients and those with low-grade T1 disease. There is a non-trivial risk of progression and nodal metastases in poorly selected patients. Wide local excision provides an oncologically sound option in patient with up to T1 disease; less evidence exists for Mohs microsurgery in the setting of penile cancer. Increasingly aggressive approaches include glansectomy and partial/radical penectomy, which provide 5- and 10-year cancer-specific survival rates of over 80%. Meticulous reconstruction is necessary for the durable function of the remaining penis. Preservation of voiding and sexual function occurs via penile skin grafting, glans resurfacing, creation of a functional penile stump, and phalloplasty with a penile implant. Perineal urethrostomy provides an alternative in pathology demanding extensive partial or radical penectomy, and a durable option for seated voiding. Clinical suspicion and timely diagnosis are paramount in terms of management as less-invasive options for earlier-stage disease develop.

The Impact of the Dermal Matrix in Tissue Reconstruction: A Bibliometric Perspective in Plastic Surgery

In the vast field of medical scientific research, few topics have managed to attract as much attention and mobilise academic resources as the use of dermal matrices in the reconstruction of soft tissue defects. In this study, we used bibliographic metrics such as co-authorship, keyword co-occurrence, and citations per document to analyse the relationship between the use of dermal matrices to reconstruct soft tissue defects caused by burns, tumours, and trauma. In addition, keyword analysis has highlighted the crucial role of technology in recent studies and the innovation brought about by the use of dermal matrices in the reconstruction of soft tissue defects. Keywords used in recent studies have revealed the critical role of technology in the development of the field. We extracted a set of 1329 research papers from the Web of Science Core Collection database between 2010 and 2024 that met our criteria. Through keyword analysis, we identified technology as a significant factor in recent studies. Our results showed that there is very little collaboration between authors on the topic and that most of them are from Asia. A significant number of articles on this topic come from the USA, China, Japan, Germany, the UK, and France. We discovered the top ten most cited sources analysing the use of dermal matrices in the reconstruction of soft tissue defects. Finally, we think that this study will be beneficial for our further research.

Testosterone Promotes Nerve Tethering and Acellular Biomaterial Perineural Fibrosis in a Rat Wound Repair Model

Objective: Nerve scarring after traumatic or iatrogenic exposure can lead to impaired function and pain. Nerve-adjacent biomaterials promoting a regenerative tissue response may help reduce perineural fibrosis. Our prior work suggests that testosterone may promote fibrotic skin scarring, but it is unknown how testosterone alters nerve fibrosis or shifts the response to biomaterials. Approach: Sterilized Lewis rats received either testosterone cypionate (+T) or placebo (-T) biweekly. Fifteen days later, wounds were created over the sciatic nerve and covered with an acellular matrix (AM) or closed via primary closure (PC). At day 42, force gauge testing measured the force required to mobilize the nerve, and wound tissue was analyzed. Results: Nerve mobilization force was greater in +T versus -T wounds (p < 0.01). Nerves tore before gliding in 60% of +T versus 6% of -T rats. Epidermal gap (p < 0.01), scar width (p < 0.01), and cross-sectional scar tissue area (p = 0.02) were greater in +T versus -T rats. +T versus -T rats expressed less Col-3 (p = 0.02) and CD68 (p = 0.02). Nerve mobilization force trended nonsignificantly higher for PC versus AM wounds and for +T versus -T wounds within the AM cohort. Innovation: Testosterone increases nerve tethering in the wound healing milieu, altering repair and immune cell balances. Conclusion: Testosterone significantly increases the force required to mobilize nerves in wound beds and elevates histological markers of scarring, suggesting that testosterone-induced inflammation may increase perineural adhesion. Testosterone may reduce the potential anti-tethering protective effect of AM. Androgen receptor antagonism may represent a therapeutic target to reduce scar-related nerve morbidity.

A Histological and Biomechanical Analysis of Human Acellular Dermis (HAD) Created Using a Novel Processing and Preservation Technique

Background

Large and complex defects requiring reconstruction are challenging for orthopaedic surgeons. The use of human acellular dermal (HAD) matrices to augment large soft tissue defects such as those seen in massive rotator cuff tears, knee extensor mechanism failures and neglected Tendo-Achilles tears has proven to be a valuable tool in surgeons reconstructive armamentarium. Different methods for allograft decellularization and preservation alter the native properties of the scaffold. Traditional processing and preservation methods have shown to have drawbacks that preclude its widespread use. Some of the common issues include inferior biomechanical properties, the risk of rejection, limited customization, difficulty in storing and transporting, the requirement of pre-operative preparation, and last but not the least increased cost.

Methods

We describe a novel processing and preservation method utilizing a two-step non-denaturing decellularization method coupled with preservation using a water-sequestering agent (glycerol) to remove immunogenic components while retaining biomechanical properties. The efficiency of this novel process was compared with the traditional freeze-drying method and verified by histological evaluation and biomechanical strength analysis.

Results

The absence of cellular components and matrix integrity in hematoxylin and eosin-stained glycerol-preserved HAD (gly-HAD) samples compared to freeze-dried HAD (FD-HAD) demonstrated effective yet gentle decellularization. Biomechanical strength analysis revealed that gly-HADs are stronger with an ultimate tensile load to the failure strength of 210 N compared to FD-HAD (124N). The gly-HADs were found to have an optimal suture-retention strength of 126 N. Finally, sterility testing of the resultant grafts was checked to ensure a sterility assurance level of 10-6 to establish implantability.

Conclusion

The novel processing and preservation technique is described in this paper to create a Human Acellular Dermis with higher biomechanical strength and superior histological characteristics. The processing and preservation technique ensured high sterility assurance levels to establish implantability.

Recent advances in the adjunctive management of diabetic foot ulcer: Focus on noninvasive technologies

Diabetic foot ulcer (DFU) is one of the most costly and serious complications of diabetes. Treatment of DFU is usually challenging and new approaches are required to improve the therapeutic efficiencies. This review aims to update new and upcoming adjunctive therapies with noninvasive characterization for DFU, focusing on bioactive dressings, bioengineered tissues, mesenchymal stem cell (MSC) based therapy, platelet and cytokine-based therapy, topical oxygen therapy, and some repurposed drugs such as hypoglycemic agents, blood pressure medications, phenytoin, vitamins, and magnesium. Although the mentioned therapies may contribute to the improvement of DFU to a certain extent, most of the evidence come from clinical trials with small sample size and inconsistent selections of DFU patients. Further studies with high design quality and adequate sample sizes are necessitated. In addition, no single approach would completely correct the complex pathogenesis of DFU. Reasonable selection and combination of these techniques should be considered.

Assessment of inflammatory suppression and fibroblast infiltration in tissue remodelling by supercritical CO2 acellular dermal matrix (scADM) utilizing Sprague Dawley models

Human skin-derived ECM aids cell functions but can trigger immune reactions; therefore it is addressed through decellularization. Acellular dermal matrices (ADMs), known for their regenerative properties, are used in tissue and organ regeneration. ADMs now play a key role in plastic and reconstructive surgery, enhancing aesthetics and reducing capsular contracture risk. Innovative decellularization with supercritical carbon dioxide preserves ECM quality for clinical use. The study investigated the cytotoxicity, biocompatibility, and anti-inflammatory properties of supercritical CO2 acellular dermal matrix (scADM) in vivo based on Sprague Dawley rat models. Initial experiments in vitro with fibroblast cells confirmed the non-toxic nature of scADM and demonstrated cell infiltration into scADMs after incubation. Subsequent tests in vitro revealed the ability of scADM to suppress inflammation induced by lipopolysaccharides (LPS) presenting by the reduction of pro-inflammatory cytokines TNF-α, IL-6, IL-1β, and MCP-1. In the in vivo model, histological assessment of implanted scADMs in 6 months revealed a decrease in inflammatory cells, confirmed further by the biomarkers of inflammation in immunofluorescence staining. Besides, an increase in fibroblast infiltration and collagen formation was observed in histological staining, which was supported by various biomarkers of fibroblasts. Moreover, the study demonstrated vascularization and macrophage polarization, depicting increased endothelial cell formation. Alteration of matrix metalloproteinases (MMPs) was analyzed by RT-PCR, indicating the reduction of MMP2, MMP3, and MMP9 levels over time. Simultaneously, an increase in collagen deposition of collagen I and collagen III was observed, verified in immunofluorescent staining, RT-PCR, and western blotting. Overall, the findings suggested that scADMs offer significant benefits in improving outcomes in implant-based procedures as well as soft tissue substitution.

Development and validation of cryopreserved or freeze-dried decellularized human dermis for transplantation

For decades, dermal tissue grafts have been used in various regenerative, reconstructive, and augmentative procedures across the body. To eliminate antigenicity and immunogenic response while still preserving the individual components and collective structural integrity of the extracellular matrix (ECM), dermis can be decellularized. Acellular dermal matrix (ADM) products like such are produced to accurately serve diverse clinical purposes. The aim of the present study is to evaluate the efficacy of a novel decellularization protocol of the human dermis, which eliminates residual human genetic material without compromising the biomechanical integrity and collagenous content of the tissue. Moreover, a freeze-drying protocol was validated. The results showed that though our decellularization protocol, human dermis can be decellularized obtaining a biocompatible matrix. The procedure is completely realized in GMP aseptic condition, avoiding tissue terminal sterilization.

Review: Implant-Based Breast Reconstruction After Mastectomy for Breast Cancer: A Meta-analysis of Randomized Controlled Trials and Prospective Studies Comparing Use of Acellular Dermal Matrix (ADM) Versus Without ADM

BACKGROUND

Breast cancer is the world's most prevalent cancer, and many breast cancer patients undergo mastectomy as the choice of treatment, often with post-mastectomy breast reconstruction. Acellular dermal matrix (ADM) use has become a method to improve outcomes of reconstruction for these patients. We aimed to compare postoperative complications and patient-reported outcomes, which are still poorly characterized, between groups utilizing acellular dermal matrix during reconstruction and those without.

MATERIALS AND METHODS

We searched electronic databases from inception to 16 June 2022 for randomized controlled trials and prospective cohort studies comparing the outcomes of patients who have and have not received acellular dermal matrix in implant-based breast reconstruction. The results were quantitatively combined and analyzed using random-effects models.

RESULTS

A total of nine studies were included, representing 3161 breasts. There was no significant difference in postoperative outcomes, such as seroma formation (p = 0.51), hematomas (p = 0.20), infections (p = 0.21), wound dehiscence (p = 0.09), reoperations (p = 0.70), implant loss (p = 0.27), or skin necrosis (p = 0.21). Only two of the studies included evaluated patient-reported outcomes between the use and non-use of ADM in implant-based breast reconstruction using BREAST-Q questionnaire, as well as self-reported pain. There was no reported significant difference in BREAST-Q or pain scores.

CONCLUSIONS

This meta-analysis shows comparable short- and long-term outcomes between ADM and non-ADM breast reconstruction, suggesting that the use of ADM may not be necessary in all cases given their additional cost. However, there is a paucity of data for patient-reported outcomes, and further research is required to determine whether ADM use affects patient-reported outcomes.

Dynamical properties of solid and hydrated collagen: Insight from nuclear magnetic resonance relaxometry

1H spin-lattice Nuclear Magnetic Resonance relaxometry experiments have been performed for collagen and collagen-based artificial tissues in the frequency range of 10 kHz-20 MHz. The studies were performed for non-hydrated and hydrated materials. The relaxation data have been interpreted as including relaxation contributions originating from 1H-1H and 1H-14N dipole-dipole interactions, the latter leading to Quadrupole Relaxation Enhancement effects. The 1H-1H relaxation contributions have been decomposed into terms associated with dynamical processes on different time scales. A comparison of the parameters for the non-hydrated and hydrated systems has shown that hydration leads to a decrease in the dipolar relaxation constants without significantly affecting the dynamical processes. In the next step, the relaxation data for the hydrated systems were interpreted in terms of a model assuming two-dimensional translational diffusion of water molecules in the vicinity of the macromolecular surfaces and a sub-diffusive motion leading to a power law of the frequency dependencies of the relaxation rates. It was found that the water diffusion process is slowed down by at least two orders of magnitude compared to bulk water diffusion. The frequency dependencies of the relaxation rates in hydrated tissues and hydrated collagen are characterized by different power laws (ωH-β, where ωH denotes the 1H resonance frequency): the first of about 0.4 and the second close to unity.

Plasticity of bone marrow-derived cell differentiation depending on microenvironments in the skin

Bone marrow-derived cells (BMDCs) are heterogeneous populations in which not only pluripotent stem cells, namely, hematopoietic stem cells (HSCs), mesenchymal stem cells (MSC) but also endothelial progenitor cells (EPC) are involved. BMDCs contribute to the maintenance of homeostasis and recovery from disrupted homeostasis as the immune, endocrine, and nervous systems. The skin is the largest organ in which various tissues, such as the epidermis, dermis, skin appendages (i.e., hair follicles), fats, muscles, and vessels, are tightly and systematically packed. It functions as a physical barrier to block the invasion of harmful substances and pathogenic microorganisms and properly regulate water evaporation. The skin is exposed to injuries from external stimuli because it is the outermost layer and owing to its specificity. Recovery from physical injuries and DNA mutations occurs constantly in the skin, but medical treatments are required for impaired wound healing. Recently, conservative treatments utilizing scaffolds have attracted attention as alternatives to surgical therapy, which is highly invasive. Against this background, numerous scaffolds are available in a clinical setting, although they have not surpassed surgery because of their distinct disadvantages. Here, we discuss the plasticity of BMDCs in the skin to maintain homeostasis, in addition to their critical roles on recovery from disrupted homeostasis. We also share our perspective on how scaffolds can be developed to establish scaffolds beyond surgery to regenerate skin structure during wound healing by maximally utilizing the plasticity of BMDCs.

Reconstruction of the human nipple-areolar complex: a tissue engineering approach

Introduction: Nipple-areolar complex (NAC) reconstruction after breast cancer surgery is challenging and does not always provide optimal long-term esthetic results. Therefore, generating a NAC using tissue engineering techniques, such as a decellularization-recellularization process, is an alternative option to recreate a specific 3D NAC morphological unit, which is then covered with an in vitro regenerated epidermis and, thereafter, skin-grafted on the reconstructed breast. Materials and methods: Human NACs were harvested from cadaveric donors and decellularized using sequential detergent baths. Cellular clearance and extracellular matrix (ECM) preservation were analyzed by histology, as well as by DNA, ECM proteins, growth factors, and residual sodium dodecyl sulfate (SDS) quantification. In vivo biocompatibility was evaluated 30 days after the subcutaneous implantation of native and decellularized human NACs in rats. In vitro scaffold cytocompatibility was assessed by static seeding of human fibroblasts on their hypodermal side for 7 days, while human keratinocytes were seeded on the scaffold epidermal side for 10 days by using the reconstructed human epidermis (RHE) technique to investigate the regeneration of a new epidermis. Results: The decellularized NAC showed a preserved 3D morphology and appeared white. After decellularization, a DNA reduction of 98.3% and the absence of nuclear and HLA staining in histological sections confirmed complete cellular clearance. The ECM architecture and main ECM proteins were preserved, associated with the detection and decrease in growth factors, while a very low amount of residual SDS was detected after decellularization. The decellularized scaffolds were in vivo biocompatible, fully revascularized, and did not induce the production of rat anti-human antibodies after 30 days of subcutaneous implantation. Scaffold in vitro cytocompatibility was confirmed by the increasing proliferation of seeded human fibroblasts during 7 days of culture, associated with a high number of living cells and a similar viability compared to the control cells after 7 days of static culture. Moreover, the RHE technique allowed us to recreate a keratinized pluristratified epithelium after 10 days of culture. Conclusion: Tissue engineering allowed us to create an acellular and biocompatible NAC with a preserved morphology, microarchitecture, and matrix proteins while maintaining their cell growth potential and ability to regenerate the skin epidermis. Thus, tissue engineering could provide a novel alternative to personalized and natural NAC reconstruction.

Acellular dermal matrix in urethral reconstruction

The management of severe urethral stricture has always posed a formidable challenge. Traditional approaches such as skin flaps, mucosal grafts, and urethroplasty may not be suitable for lengthy and intricate strictures. In the past two decades, tissue engineering solutions utilizing acellular dermal matrix have emerged as potential alternatives. Acellular dermal matrix (ADM) is a non-immunogenic biological collagen scaffold that has demonstrated its ability to induce layer-by-layer tissue regeneration. The application of ADM in urethral reconstruction through tissue engineering has become a practical endeavor. This article provides an overview of the preparation, characteristics, advantages, and disadvantages of ADM along with its utilization in urethral reconstruction via tissue engineering.

Applications of Synthetic Hybrid-Scale Fiber Matrix in Head and Neck Reconstruction: A Case Series

Introduction

Patients with head and neck cancer often necessitate complex reconstructions, considering both functional and esthetic concerns. Reconstructions are further complicated by previous radiation therapy and patient co-morbidities, which impair wound healing. A recently introduced synthetic hybrid-scale fiber matrix has been shown to provide durable wound coverage and promote tissue healing as an alternative to traditional biologic allogenic and xenogenic skin substitutes.

Case Presentation

Thirteen patients were treated at a single academic hospital between December 1, 2021, and May 1, 2023 with the synthetic matrix in head and neck reconstructions. Reconstructions included exposed muscle, scalp wounds, intra-oral defects, and radial forearm free flap donor sites. Wound sizes ranged from 2 × 2 cm to 18 × 10 cm. Serial photographs were taken to evaluate wound healing at 1, 4, 8, 12, and 16 weeks timepoints after application. Outcomes measured at each timepoint included wound size, presence of granulation tissue, and extent of epithelialization. No hematomas or wound complications were encountered. Complete wound healing was noted between 6 and 12 weeks, dependent on wound size. The synthetic matrix significantly promoted wound healing via early granulation tissue formation and epithelialization, or mucosalization, in all head and neck applications. Scar formation and contracture were acceptable in all cases.

Conclusion

The use of synthetic hybrid-scale fiber matrix promotes wound healing and avoids patient morbidity associated with traditional allogenic and biogenic treatments, such as split-thickness skin grafts. This synthetic matrix has been demonstrated to be a valuable asset in the head and neck reconstructive armamentarium.

Healing of a bone-exposed soft tissue defect after surgical correction of traumatic patellar dislocation: A case report

RATIONALE

Reconstructive surgery is widely considered the primary treatment for soft tissue defects around the knee owing to its high flexibility. However, in our recent case study, we explored an alternative approach using decellularized collagen dressings, which proved highly effective in healing a soft tissue defect involving bone exposure following surgical correction of a traumatic patellar dislocation.

PATIENT CONCERNS

A 65-year-old male with a traumatic patellar dislocation in the lower extremity failed to approximate the wound after surgical correction. The patient refused additional surgical reconstruction because of the potential risks of multiple operative complications.

DIAGNOSES

Traumatic patellar dislocation complicated by exposed bone following surgical treatment was made.

INTERVENTIONS

The procedure was performed using ABCcolla® Collagen Matrix (ACRO Biomedical, Taiwan), an acellular dermal matrix made from a decellularized native porcine collagen scaffold dressing. Collagen dressings were applied to the soft tissue defect, and biointegration was observed in the wound area of bone exposure.

OUTCOMES

Through the application of ABCcolla® Collagen Matrix (ACRO Biomedical, Taiwan) and diligent wound care for a total of 105 days, the patient healed successfully and achieved partial functional recovery after undergoing rehabilitation. During recent outpatient clinic visits, the patient is now able to ambulate independently with the aid of crutches.

LESSONS

Collagen dressings circumvent the potential risks and complications associated with multiple surgical procedures. We believe that the utilization of collagen dressings, combined with careful wound management, could serve as a promising alternative treatment option for patients with soft tissue defects around the knee in the future.

Delivery of adipose-derived growth factors from heparinized adipose acellular matrix accelerates wound healing

Dermal white adipocytes are closely associated with skin homeostasis and wound healing. However, it has not been fully investigated whether adipose-derived products improve wound healing. Here, we obtained adipose acellular matrix (AAM) and adipose-derived growth factors (ADGFs) from human adipose tissue and fabricated an ADGF-loaded AAM via surface modification with heparin. The product, HEP-ADGF-AAM, contained an adipose-derived scaffold and released ADGFs in a controlled fashion. To test its efficacy in promoting wound healing, mice with full thickness wound received three different treatments: HEP-ADGF-AAM, AAM and ADM. Control mice received no further treatments. Among these treatments, HEP-ADGF-AAM best improved wound healing. It induced adipogenesis in situ after in vivo implantation and provided an adipogenic microenvironment for wounds by releasing ADGFs. HEP-ADGF-AAM not only induced adipocyte regeneration, but also enhanced fibroblast migration, promoted vessel formation, accelerated wound closure, and enhanced wound epithelialization. Moreover, there was a close interaction between HEP-ADGF-AAM and the wound bed, and collagen was turned over in HEP-ADGF-AAM. These results show that HEP-ADGF-AAM might substantially improve re-epithelialization, angiogenesis, and skin appendage regeneration, and is thus a promising therapeutic biomaterial for skin wound healing.

Short- and Long-term Outcomes of an Acellular Dermal Substitute versus Standard of Care in Burns and Reconstructions: A Phase I/II Intrapatient Randomized Controlled Trial

OBJECTIVE

Dermal substitutes promote dermal regeneration and improve scar quality, but knowledge gaps remain regarding their efficacy and indications for use. The authors investigated the safety and short- and long-term efficacy of an acellular dermal substitute in patients with full-thickness wounds.

METHODS

This intrapatient randomized controlled, open-label, phase I (safety) and phase II (efficacy) study compared treatment with Novomaix (Matricel GmbH), a dermal collagen/elastin-based scaffold, with split-thickness skin graft (STSG) only. The primary safety outcome was graft take at 5 to 7 days postsurgery. Postsurgical scar quality was assessed by measuring elasticity, color, and scores on the Patient and Observer Scar Assessment Scale at 3 months, 12 months, and 6 years.

RESULTS

Twenty-five patients were included, of which 24 received treatment allocation. Graft take and wound healing were statistically significantly lower/delayed in the dermal matrix group compared with STSG alone (P < .004). Serious adverse events were delayed epithelialization in four dermal matrix and three STSG study areas. At 12 months postsurgery, skin extension (P = .034) and elasticity (P = .036) were better for the dermal matrix group compared with the group receiving STSG alone. Other scar quality parameters at 12 months and 6 years did not differ between treatment arms.

CONCLUSIONS

The dermal substitute was a safe treatment modality for full-thickness wounds. Compared with STSG alone, time to wound healing was slightly increased. Nevertheless, scar quality at 12 months seemed somewhat improved in the wounds treated with the dermal substitute, indicative of enhanced scar maturation. In the long term, final scar quality was similar for both treatment modalities.

A novel optical coherence tomography-based in vitro method of anti-aging skin analysis using 3D skin wrinkle mimics

BACKGROUND

Wrinkles represent a characteristic symptom of skin aging. In recent years, various studies have focused on their prevention and/or cure. However, clinical tests are still the only method available to directly detect and evaluate the anti-wrinkle efficacy of various substances. Moreover, no in vitro strategy for such anti-aging skin analysis has been reported. Therefore, in this study, we aimed to develop a novel technology to overcome these limitations.

MATERIALS AND METHODS

Full-thickness (FT) skin wrinkle mimics with various widths and depths were fabricated using a collagen stamping method. These were analyzed and compared using 2D and 3D Swept Source-Optical Coherence Tomography (SS-OCT) imaging technologies.

RESULTS

SS-OCT demonstrated superficial and cross-sectional images of the wrinkle mimics, and the size of the wrinkles was validated using image analysis. Retinoic acid treatment significantly decreased both the depth and width of wrinkles formed in the FT skin wrinkle mimics.

CONCLUSIONS

Using 3D tissue engineering and SS-OCT imaging technologies, we developed a novel in vitro technique that can directly detect skin wrinkles. This significantly efficient method could lead to an alternative strategy for animal experiments and preclinical anti-aging research on the skin.

Reconstruction of Hand and Foot Defects with Free Serratus Carpaccio Flap and Free Serratus Fascia Flap: A Comparative Retrospective Study of Surgical Outcomes

BACKGROUND

Defects of the hand and foot often require an individualized reconstructive approach, due to their unique functional and aesthetic characteristics. Transferred tissues should be thin, pliable, and durable, with free fascial flaps meeting these requirements. This study aimed to evaluate the serratus fascia flap and the serratus carpaccio flap, which is a modification of the fascia flap, by including a thin muscle layer, with the goal of enhancing flap resilience and lowering morbidity rates.

METHODS

Between January 2000 and December 2017, 31 patients underwent microsurgical reconstruction of the hand or foot either by serratus fascia flap (fascia group) or serratus carpaccio flap (carpaccio group). The serratus fascia flaps were mainly harvested between 2000 and 2012, and the serratus carpaccio flaps between 2013 and 2017. Patient records were reviewed retrospectively, regarding demographics, complications, overall flap survival, additional revision surgeries, and surgical outcome. Categorical variables were compared using Fisher's exact test and continuous data with the Mann-Whitney tests. Logistic regression was used to examine the correlation between comorbidities and postoperative complication rates. Differences were considered significant when p < 0.05.

RESULTS

The fascia group consisted of 17 patients and the carpaccio group of 14 patients. The average patient age in the fascia group was 39.2 ± 10.5 years, and it was 39.1 ± 14.7 years in the carpaccio group. Overall complication rates were significantly lower in the carpaccio group than in the fascia group (28.6% vs. 70.6%, p = 0.03). The rates of overall flap survival (85.7% in the carpaccio group vs. 74.5% in the fascia group, p = 0.66) and partial flap loss (14.3% in the carpaccio group vs. 47.1% in the fascia group, p = 0.07) did not differ significantly among both groups. One postoperative hematoma of the donor site requiring revision surgery was reported in the carpaccio group (7.1%, p = 0.45) while no donor-site morbidity was reported in the fascia group.

CONCLUSIONS

Our findings indicate that the serratus carpaccio flap presents a promising alternative to the serratus fascia flap. This modification has proven to be effective in substantially reducing postoperative complications requiring additional surgical interventions. Therefore, the serratus carpaccio flap can be considered a dependable reconstructive option for addressing complex soft tissue defects of the hand and foot, with complication rates that are within an acceptable range.

Acellular dermal matrix in reconstructive surgery: Applications, benefits, and cost

Modern tissue engineering has made substantial advancements that have revolutionized plastic surgery. Acellular dermal matrix (ADM) is an example that has gained considerable attention recently. ADM can be made from humans, bovines, or porcine tissues. ADM acts as a scaffold that incorporates into the recipient tissue. It is gradually infiltrated by fibroblasts and vascularized. Fortunately, many techniques have been used to remove cellular and antigenic components from ADM to minimize immune system rejection. ADM is made of collagen, fibronectin, elastin, laminin, glycosaminoglycans, and hyaluronic acid. It is used in critical wounds (e.g., diabetic wounds) to protect soft tissue and accelerate wound healing. It is also used in implant-based breast reconstruction surgery to improve aesthetic outcomes and reduce capsule contracture risk. ADM has also gained attention in abdominal and chest wall defects. Some studies have shown that ADM is associated with less erosion and infection in abdominal hernias than synthetic meshes. However, its higher cost prevents it from being commonly used in hernia repair. Also, using ADM in tendon repair (e.g., Achilles tendon) has been associated with increased stability and reduced rejection rate. Despite its advantages, ADM might result in complications such as hematoma, seroma, necrosis, and infection. Moreover, ADM is expensive, making it an unsuitable option for many patients. Finally, the literature on ADM is insufficient, and more research on the results of ADM usage in surgeries is needed. This article aims to review the literature regarding the application, Benefits, and costs of ADM in reconstructive surgery.

Direct-to-Implant Subcutaneous Breast Reconstruction: A Systematic Review of Complications and Patient's Quality of Life

BACKGROUND

The use of direct-to-implant subcutaneous breast reconstruction has increased over the last years. The goal of this systematic review is to deliver an updated review of the safety of this technique and its impact on quality of life. We also compare subcutaneous vs submuscular complications, through meta-analysis.

METHODS

Literature review through PubMed and Cochrane Library databases were performed by PRISMA criteria. Thirty-nine studies met inclusion criteria for subcutaneous review and 15 studies met inclusion criteria for meta-analysis. All included studies were evaluated for complications and answers to the BREAST-Q. Data were analysed using Microsoft Excel, IBM SPSS, and Cochrane RevMan.

RESULTS

In 2863 patients and 3988 breasts that undergone direct to implant subcutaneous breast reconstruction, 8,21% had rippling, 5,64% seroma, 1,74% hematoma, 3,40% infection, 3,01% wound dehiscence, 3,93% skin necrosis, 3,34% nipple-areolar-complex (NAC) necrosis, 3,07% capsular contracture, 0,00% animation deformity, and 3,83% an implant removal. Meta-analysis showed a statistically significant decrease in the odds ratio of animation deformity, a but statistically significant higher odds ratio of rippling. Subcutaneous and submuscular reconstructions had similar BREAST-Q scores.

CONCLUSIONS

Direct-to-implant subcutaneous breast reconstruction does not harm the patient's quality of life, comparatively with submuscular, saving the pectoral muscle from dissection and preventing animation deformity, but increasing the risk of rippling.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

In Situ Cross-Linked Collagen-Based Biological Patch Integrating Anti-Infection and Anti-Calcification Properties

Acellular dermal matrix (ADM) can be used as collagen-based biological patches for regeneration and repair of soft tissues in vivo. However, the problems of calcification and infection during treatment with patches can lead to premature patch failure and even to a severely increased risk of recurrence. In this study, first, porcine ADM (pADM) grafted with vinyl underwent an in situ cross-linking reaction in the presence of an initiator, while quaternary ammonium groups were introduced into the pADM during the cross-linking process to obtain MA-DMC-pADM, which is a biological patch with anti-infection and anti-calcification properties. The results of physicochemical property tests of the material showed that the pADM after cross-linking had better physical and mechanical properties. Importantly, antibacterial and anti-calcification experiments showed that MA-DMC-pADM had a good antibacterial and anti-calcification effect. Therefore, the MA-DMC-pADM biological patch facilitates their longer-lasting effectiveness, allowing pADM to be used in a wider range of applications.

Braxon®-assisted prepectoral breast reconstruction: A decade later

We are sitting on the cusp of the bioengineered breast era, in which implant-based breast reconstruction is seeing a growing trend and biotechnology research progressively empowers clinical practice. As never before, the choice of biomaterials has acquired great importance for achieving reconstructive outcomes, and the increase in the use of acellular dermal matrices (ADMs) in the field of senology tells us a story of profound upheaval and progress. With the advent of prepectoral breast reconstruction (PPBR), plenty of devices have been proposed to wrap the silicone prosthesis, either completely or partially. However, this has caused a great deal of confusion and dissent with regard to the adoption of feasible reconstructive strategies as well as the original scientific rationale underlying the prepectoral approach. Braxon^® is the very first device that made prepectoral implant positioning possible, wrapping around the prosthesis and exerting the proven ADM regenerative potential at the implant–tissue interface, taking advantage of the body's physiological healing mechanisms. To date, the Braxon^® method is among the most studied and practiced worldwide, and more than 50 publications confirm the superior performance of the device in the most varied clinical scenarios. However, a comprehensive record of the working of this pioneering device is still missing. Therefore, our aim with this review is to lay a structured knowledge of surgery with BRAXON^® and to provide a decision-making tool in the field of PPBR through a complete understanding on the very first device for prepectoral, one decade after its introduction.

Pre-Pectoral One-Stage Breast Reconstruction with Anterior Coverage Using Superior Anterior Biological Acellular Dermal Matrix (ADM) and Inferior Anterior Dermal Sling Support

The use of acellular dermal matrix (ADM) implants has enhanced breast reconstruction. ADM is a biotechnologically designed human tissue of bovine or porcine origin in which tissue processing removes cellular antigens. In this case report, we describe the use of ADM in one-stage prepectoral breast reconstruction. Skin-reduction breast reconstruction with a prepectoral implant was performed. We created a combined dermal pocket using the inferior dermal flap, sutured with a patch of acellular dermal matrix to continue its extension until the upper pole, to cover the implant. This technique offers single-stage immediate reconstruction, with a decreased requirement for ADM and increased use of vascularized tissue and implant support. Additionally, in the pre-pectoral space, decreased pain postoperatively and less anatomic disruption is offered.

Application of Acellular Dermal Matrix in Gynaecology—A Current Review

The aim of our study is to draw attention to the multitude of applications of acellular dermal matrix (ADM) in the surgical treatment of urogynaecological disorders, such as reduction in the reproductive organs, and in reconstructive gynaecology. Despite the existence of numerous operational methods and materials, the effectiveness of transvaginal operation is still insufficient. Native tissue operations are often not durable enough, while operations with synthetic materials have numerous side effects, such as infections, hematomas, vaginal erosion, or dyspareunia. Hence, the search continues for a different material with a better efficacy and safety profile than those previously mentioned. It seems that ADM can meet these requirements and be a useful material for urogynaecological surgery. Key words related to the usage of ADM in gynaecological reconstructive surgery were used to search relevant databases (NCBI MedLine, Clinical Key, Clinicaltrials.gov). This manuscript is based on 43 literature sources, 28 (65.11%) of which were released after 2016. Older sources are cited for the purpose of presenting basic science, or other important issues related to the manuscript. ADM seems to be an ideal material for urogynaecological and reconstructive surgery. It has high durability, and thus high effectiveness. Moreover, it does not have the side effects typical for synthetic materials. There are no reports of material rejection, erosion or dyspareunia directly related to the presence of the mesh. Due to the difficulties in obtaining ADM and the need to perform additional tests, this material is not common in routine clinical practice. Therefore, the number of cases and the size of the research groups are insufficient to clearly define the potential of mesh from biological tissue. However, the results are so promising that it is worth considering a wider introduction to the use of this material. Our hope is that increasing clinicians’ awareness of this topic will lead to more studies comparing methods using native tissues or synthetic materials and those using ADM.