A novel chemotactic factor derived from the extracellular matrix protein decorin recruits mesenchymal stromal cells in vitro and in vivo

Surgical management of perianal fistula using an ovine forestomach matrix implant

PURPOSE

Invasive surgical management of cryptoglandular perianal fistulas (PF) is challenging because of high recurrence rates and the potential for injury to the sphincter complex. In the present technical note, we introduce a minimally invasive treatment for PF using a perianal fistula implant (PAFI) comprising ovine forestomach matrix (OFM).

METHODS

This retrospective observational case series highlights 14 patients who had undergone a PAFI procedure at a single center between 2020 and 2023. During the procedure, previously deployed setons were removed and tracts were de-epithelialized with curettage. OFM was rehydrated, rolled, passed through the debrided tract, and secured in place at both openings with absorbable suture. Primary outcome was fistula healing at 8 weeks, and secondary outcomes included recurrence or postoperative adverse events.

RESULTS

Fourteen patients underwent PAFI using OFM with a mean follow-up period of 37.6 ± 20.1 weeks. In follow-up, 64% (n = 9/14) had complete healing at 8 weeks and all remained healed, except one at last follow-up visit. Two patients underwent a second PAFI procedure and were healed with no recurrence at the last follow-up visit. Of all patients that healed during the study period (n = 11), the median time to healing was 3.6 (IQR 2.9-6.0) weeks. No postprocedural infections nor adverse events were noted.

CONCLUSIONS

The minimally invasive OFM-based PAFI technique for PF treatment was demonstrated to be a safe and feasible option for patients with trans-sphincteric PF of cryptoglandular origin.

Probing the effects of matrix-derived microcarrier composition on human adipose-derived stromal cells cultured dynamically within spinner flask bioreactors

Recognizing the cell-instructive capacity of the extracellular matrix (ECM), this study investigated the effects of expanding human adipose-derived stromal cells (hASCs) on ECM-derived microcarriers fabricated from decellularized adipose tissue (DAT) or decellularized cartilage tissue (DCT) within spinner flask bioreactors. Protocols were established for decellularizing porcine auricular cartilage and electrospraying methods were used to generate microcarriers comprised exclusively of DAT or DCT, which were compositionally distinct, but had matching Young's moduli. Both microcarrier types supported hASC attachment and growth over 14 days within a low-shear spinner culture system, with a significantly higher cell density observed on the DCT microcarriers at 7 and 14 days. Irrespective of the ECM source, dynamic culture on the microcarriers altered the expression of genes and proteins associated with cell adhesion and ECM remodeling. Label-free mass spectrometry analysis showed upregulation of proteins associated with cartilage development and ECM in the hASCs expanded on the DCT microcarriers. Based on Luminex analysis, the hASCs expanded on the DCT microcarriers secreted significantly higher levels of IL-8 and PDGFAA, supporting that the ECM source can modulate hASC paracrine factor secretion. Finally, the hASCs expanded on the microcarriers were extracted for analysis of adipogenic and chondrogenic differentiation relative to baseline controls. The microcarrier-cultured hASCs showed enhanced intracellular lipid accumulation at 7 days post-induction of adipogenic differentiation. In the chondrogenic studies, a low level of differentiation was observed in all groups. Future studies are warranted using alternative cell sources with greater chondrogenic potential to further assess the chondro-inductive properties of the DCT microcarriers.

Biomaterial Integration in the Joint: Pathological Considerations, Immunomodulation, and the Extracellular Matrix

Defects of articular joints are becoming an increasing societal burden due to a persistent increase in obesity and aging. For some patients suffering from cartilage erosion, joint replacement is the final option to regain proper motion and limit pain. Extensive research has been undertaken to identify novel strategies enabling earlier intervention to promote regeneration and cartilage healing. With the introduction of decellularized extracellular matrix (dECM), researchers have tapped into the potential for increased tissue regeneration by designing biomaterials with inherent biochemical and immunomodulatory signals. Compared to conventional and synthetic materials, dECM-based materials invoke a reduced foreign body response. It is therefore highly beneficial to understand the interplay of how these native tissue-based materials initiate a favorable remodeling process by the immune system. Yet, such an understanding also demands increasing considerations of the pathological environment and remodeling processes, especially for materials designed for early disease intervention. This knowledge would avoid rejection and help predict complications in conditions with inflammatory components such as arthritides. This review outlines general issues facing biomaterial integration and emphasizes the importance of tissue-derived macromolecular components in regulating essential homeostatic, immunological, and pathological processes to increase biomaterial integration for patients suffering from joint degenerative diseases. This article is protected by copyright. All rights reserved.

Further structural characterization of ovine forestomach matrix and multi-layered extracellular matrix composites for soft tissue repair

Decellularized extracellular matrix (dECM)-based biomaterials are of great clinical utility in soft tissue repair applications due to their regenerative properties. Multi-layered dECM devices have been developed for clinical indications where additional thickness and biomechanical performance are required. However, traditional approaches to the fabrication of multi-layered dECM devices introduce additional laminating materials or chemical modifications of the dECM that may impair the biological functionality of the material. Using an established dECM biomaterial, ovine forestomach matrix, a novel method for the fabrication of multi-layered dECM constructs has been developed, where layers are bonded via a physical interlocking process without the need for additional bonding materials or detrimental chemical modification of the dECM. The versatility of the interlocking process has been demonstrated by incorporating a layer of hyaluronic acid to create a composite material with additional biological functionality. Interlocked composite devices including hyaluronic acid showed improved in vitro bioactivity and moisture retention properties.

Distal Lung Microenvironment Triggers Release of Mediators Recognized as Potential Systemic Biomarkers for Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disease with an unmet need of biomarkers that can aid in the diagnostic and prognostic assessment of the disease and response to treatment. In this two-part explorative proteomic study, we demonstrate how proteins associated with tissue remodeling, inflammation and chemotaxis such as MMP7, CXCL13 and CCL19 are released in response to aberrant extracellular matrix (ECM) in IPF lung. We used a novel ex vivo model where decellularized lung tissue from IPF patients and healthy donors were repopulated with healthy fibroblasts to monitor locally released mediators. Results were validated in longitudinally collected serum samples from 38 IPF patients and from 77 healthy controls. We demonstrate how proteins elevated in the ex vivo model (e.g., MMP7), and other serum proteins found elevated in IPF patients such as HGF, VEGFA, MCP-3, IL-6 and TNFRSF12A, are associated with disease severity and progression and their response to antifibrotic treatment. Our study supports the model’s applicability in studying mechanisms involved in IPF and provides additional evidence for both established and potentially new biomarkers in IPF.

Retrospective real-world comparative effectiveness of ovine forestomach matrix and collagen/ORC in the treatment of diabetic foot ulcers

The retrospective pragmatic real‐world data (RWD) study compared the healing outcomes of diabetic foot ulcers (DFUs) treated with either ovine forestomach matrix (OFM) (n = 1150) or collagen/oxidised regenerated cellulose (ORC) (n = 1072) in out‐patient wound care centres. Median time to wound closure was significantly (P = .0015) faster in the OFM group (14.6 ± 0.5 weeks) relative to the collagen/ORC group (16.4 ± 0.7). A sub‐group analysis was performed to understand the relative efficacy in DFUs requiring longer periods of treatment and showed that DFUs treated with OFM healed up to 5.3 weeks faster in these challenging wounds. The percentage of wounds closed at 36 weeks was significantly improved in OFM treated DFUs relative to the collagen/ORC. A Cox proportional hazards analysis showed OFM‐treated wounds had a 18% greater probability of healing versus wounds managed with collagen/ORC, and the probability increased to 21% when the analysis was adjusted for multiple variables. This study represents the first large retrospective RWD analysis comparing OFM and collagen/ORC and supports the clinical efficacy of OFM in the treatment of DFUs.

Neural Tissue Homeostasis and Repair Is Regulated via CS and DS Proteoglycan Motifs

Chondroitin sulfate (CS) is the most abundant and widely distributed glycosaminoglycan (GAG) in the human body. As a component of proteoglycans (PGs) it has numerous roles in matrix stabilization and cellular regulation. This chapter highlights the roles of CS and CS-PGs in the central and peripheral nervous systems (CNS/PNS). CS has specific cell regulatory roles that control tissue function and homeostasis. The CNS/PNS contains a diverse range of CS-PGs which direct the development of embryonic neural axonal networks, and the responses of neural cell populations in mature tissues to traumatic injury. Following brain trauma and spinal cord injury, a stabilizing CS-PG-rich scar tissue is laid down at the defect site to protect neural tissues, which are amongst the softest tissues of the human body. Unfortunately, the CS concentrated in gliotic scars also inhibits neural outgrowth and functional recovery. CS has well known inhibitory properties over neural behavior, and animal models of CNS/PNS injury have demonstrated that selective degradation of CS using chondroitinase improves neuronal functional recovery. CS-PGs are present diffusely in the CNS but also form denser regions of extracellular matrix termed perineuronal nets which surround neurons. Hyaluronan is immobilized in hyalectan CS-PG aggregates in these perineural structures, which provide neural protection, synapse, and neural plasticity, and have roles in memory and cognitive learning. Despite the generally inhibitory cues delivered by CS-A and CS-C, some CS-PGs containing highly charged CS disaccharides (CS-D, CS-E) or dermatan sulfate (DS) disaccharides that promote neural outgrowth and functional recovery. CS/DS thus has varied cell regulatory properties and structural ECM supportive roles in the CNS/PNS depending on the glycoform present and its location in tissue niches and specific cellular contexts. Studies on the fruit fly, Drosophila melanogaster and the nematode Caenorhabditis elegans have provided insightful information on neural interconnectivity and the role of the ECM and its PGs in neural development and in tissue morphogenesis in a whole organism environment.

Extracellular matrix graft for reconstruction over exposed structures: a pilot case series

OBJECTIVE

Soft tissue defects, especially those involving exposed vital structures, present a reconstructive challenge because poor vascularity of such defects typically makes immediate skin grafting unviable. Where flap procedures are inappropriate or not possible, dermal matrices represent an alternative reconstructive option for defects with denuded vital structures. With dermal matrices becoming increasingly available and technologically advanced, we evaluated an ovine-derived extracellular matrix graft in the reconstruction of complex soft tissue defects involving exposed vital structures.

METHOD

Six cases of soft tissue defects exhibiting denuded vital structures underwent reconstruction using an ovine forestomach matrix graft as a dermal matrix. Grafts were fixed directly into defects for immediate coverage and subsequently temporised defects via granulation tissue formation for later skin graft or secondary closure. Defect granulation and epithelialisation were monitored until closure and the final aesthetic and functional outcomes were evaluated.

RESULTS

Complete healing was achieved in all cases, with defect granulation becoming observable within one to two weeks and complete granulation occurring within one to six weeks. Granulation tissue resulting from the graft was suitable for skin grafting, with 100% take of skin grafts after one week and complete re-epithelialisation in two to three weeks in the four cases that received a skin graft. Good cosmetic, functional and patient satisfaction outcomes were achieved in all cases.

CONCLUSION

The present series demonstrates our initial use of an extracellular matrix-based dermal matrix in reconstructing defects with exposed vital structures. While such dermal matrices do not supersede or replace flap procedures, they represent an alternative option on the reconstructive ladder in cases where flap procedures are not appropriate or possible.

A Polymer-Biologic Hybrid Hernia Construct: Review of Data and Early Experiences

Surgical mesh reinforcement of the human abdominal wall has been found to reduce the chance of recurrence in hernia repairs. While traditionally polymer meshes have been used in hernia repair, alternative mesh options have been engineered to prevent the inflammatory foreign body response invoked by polymers. A reinforced tissue matrix (RTM) mesh has been developed by embedding a polymer within a decellularized extracellular matrix. This combination has been attributed to the recruitment of host cells, a pro-healing response, and attenuation of the foreign body response. This has been observed to lead to the regeneration of functional tissue within the repair site that is reinforced by the polymer to offload abdominal pressures over time. This manuscript presents the review of OviTex, an RTM, in several types of hernia repair. The authors have found that the use of RTM in hernia repair is effective in preventing foreign body response, promoting wound healing, and providing reinforcement to lower the risk of hernia recurrence.

Extracellular matrix graft for the surgical management of Hurley stage III hidradenitis suppurativa: a pilot case series

Objective:

Surgical management of Hurley stage III hidradenitis suppurativa (HS) typically involves the excision of diseased tissue and subsequent reconstruction, potentially leading to complications or recurrence of the disease. This pilot case series sought to evaluate a decellularised ovine forestomach matrix (OFM) extracellular matrix (ECM) graft for soft tissue regeneration as part of surgical reconstruction of stage III HS of the axilla.

Method:

The prospective pilot case series involved six participants and a total of eight defects. The ECM graft was used either as a dermal substitute for a staged reconstruction (n=3 defects) or as an implant under a fasciocutaneous flap (n=5 defects) following wide excision of the diseased tissue.

Results:

In all cases complete healing was achieved, with no major surgical complications. When used as a dermal substitute the OFM graft was completely granulated within 2–4 weeks, with defects closing by secondary intention or following placement of a split-thickness skin graft. When used as an implant beneath a fasciocutaneous flap, healing of the surgical sites was observed after 1–3 months. At the long-term follow-up (3–12 months), all participants had excellent range of motion and none had reported disease recurrences.

Conclusion:

This pilot case series explored the implementation of an ECM graft as part of the surgical management of axilla Hurley stage III HS. Although the study had a limited number of participants, long-term outcomes were promising and suggest further studies are warranted.

Correction: A novel chemotactic factor derived from the extracellular matrix protein decorin recruits mesenchymal stromal cells in vitro and in vivo

[This corrects the article DOI: 10.1371/journal.pone.0235784.].