A tri-layer decellularized, dehydrated human amniotic membrane scaffold supports the cellular functions of human tenocytes in vitro.

Differences in scaffold design have the potential to influence cell-scaffold interactions. This study sought to determine whether a tri-layer design influences the cellular function of human tenocytes in vitro. The single-layer decellularized, dehydrated human amniotic membrane (DDHAM) and the tri-layer DDHAM (DDHAM-3L) similarly supported tenocyte function as evidenced by improved cell growth and migration, reduced dedifferentiation, and an attenuated inflammatory response. The tri-layer design provides a mechanically more robust scaffold without altering biological activity.

Placental-Derived Biomaterials and Their Application to Wound Healing: A Review.

Chronic wounds are associated with considerable patient morbidity and present a significant economic burden to the healthcare system. Often, chronic wounds are in a state of persistent inflammation and unable to progress to the next phase of wound healing. Placental-derived biomaterials are recognized for their biocompatibility, biodegradability, angiogenic, anti-inflammatory, antimicrobial, antifibrotic, immunomodulatory, and immune privileged properties. As such, placental-derived biomaterials have been used in wound management for more than a century. Placental-derived scaffolds are composed of extracellular matrix (ECM) that can mimic the native tissue, creating a reparative environment to promote ECM remodeling, cell migration, proliferation, and differentiation. Reliable evidence exists throughout the literature to support the safety and effectiveness of placental-derived biomaterials in wound healing. However, differences in source (i.e., anatomical regions of the placenta), preservation techniques, decellularization status, design, and clinical application have not been fully evaluated. This review provides an overview of wound healing and placental-derived biomaterials, summarizes the clinical results of placental-derived scaffolds in wound healing, and suggests directions for future work.

Time to Revision After Periprosthetic Joint Infection in Total Ankle Arthroplasty: A Systematic Review.

While not a common complication after total ankle arthroplasty (TAA), periprosthetic joint infection (PJI) presents a significant risk of implant failure. The primary aim of this systematic review was to evaluate time to revision after PJI in patients who had undergone TAA. An extensive search strategy via electronic databases initially captured 11,608 citations that were evaluated for relevance. Ultimately, 12 unique articles studying 3040 implants met inclusion criteria. The time to revision surgery due to PJI was recorded for each study and a weighted average obtained. The prevalence of PJI was 1.12% (n = 34). We found that the average time to revision due to PJI was 30.7 months, or approximately 2.6 years after the index TAA procedure. By literature definitions, the majority of cases (91.2%, n = 31) were beyond the "acute" PJI phase. The population was divided into 2 groups for further analysis of chronic infections. PJIs before the median were classified as "early" and those after as "late" chronic. The majority of cases (61.8%) were late chronic with an average time to revision of 44.3 months. A smaller number were early chronic (29.4%) with revision within 10.8 months. After summarizing the rates of infection and times to revision reported in the literature, we suggest modifying the current PJI classification to include early chronic and late chronic subgroups so that the total ankle surgeon is better prepared to prudently diagnose and treat PJIs.

An in vitro comparison of human corneal epithelial cell activity and inflammatory response on differently designed ocular amniotic membranes and a clinical case study.

Amniotic membrane (AM) is a naturally derived biomaterial with biological and mechanical properties important to Ophthalmology. The epithelial side of the AM promotes epithelialization, while the stromal side regulates inflammation. However, not all AMs are equal. AMs undergo different processing with resultant changes in cellular content and structure. This study evaluates the effects of sidedness and processing on human corneal epithelial cell (HCEC) activity, the effect of processing on HCEC inflammatory response, and then a case study is presented. Three differently processed, commercially available ocular AMs were selected: (1) Biovance®3L Ocular, a decellularized, dehydrated human AM (DDHAM), (2) AMBIO2®, a dehydrated human AM (DHAM), and (3) AmnioGraft®, a cryopreserved human AM (CHAM). HCECs were seeded onto the AMs and incubated for 1, 4 and 7 days. Cell adhesion and viability were evaluated using alamarBlue assay. HCEC migration was evaluated using a scratch wound assay. An inflammatory response was induced by TNF-α treatment. The effect of AM on the expression of pro-inflammatory genes in HCECs was compared using quantitative polymerase chain reaction (qPCR). Staining confirmed complete decellularization and the absence of nuclei in DDHAM. HCEC activity was best supported on the stromal side of DDHAM. Under inflammatory stimulation, DDHAM promoted a higher initial inflammatory response with a declining trend across time. Clinically, DDHAM was used to successfully treat anterior basement membrane dystrophy. Compared with DHAM and CHAM, DDHAM had significant positive effects on the cellular activities of HCECs in vitro, which may suggest greater ocular cell compatibility in vivo.

The effect of a silver hydrogel sheet dressing on postsurgical incision healing after foot and ankle surgery.

Introduction: Silver hydrogel dressings are antimicrobial dressings with the potential to aid post-surgical healing. The purpose of this study is to evaluate the effects of a silver hydrogel dressing on postoperative scarring and complications. Methods: 40 foot and ankle patients (48.43 ± 16.82 years) were included in the study with 20 patients in each group. Postoperatively, the treatment group was treated with a silver hydrogel sheet dressing, and the control group was treated with a standard petroleum-based dressing. Follow-up was performed at two, six, and 12 weeks. Postoperative scarring and complications were evaluated and compared between groups. Scarring was evaluated using the Patient and Observer Scar Assessment Scale (POSAS). Scar length and width were measured using digital calipers and used to compute scar area. Results: The treatment group demonstrated statistically significant improvements in the POSAS observer score and observer opinion at six and 12 weeks (p < 0.001). Additionally, patient reported pain was significantly lower for the treatment group than the control group at 12 weeks (p < 0.001). Patient reported itch declined across time for both groups (p < 0.001) with significantly less itching reported by the treatment group (p = 0.027). Scar area was also significantly lower for the treatment group than the control group at six weeks and 12 weeks (p ≤ 0.002). Neither group experienced any postoperative complications. Conclusion: These results suggest that the inherent properties of the silver hydrogel dressing may improve postsurgical scarring. Lay Summary: Surgical incisions result in scar, which can present both cosmetic and rehabilitation concerns after foot or ankle surgery. It is standard to use a petroleum-based dressing on incisions after surgery, however, advancements in incisional dressings have been made over the past 20 years. One such advancement is silver-impregnated hydrogel sheet dressings which have been shown to maintain a moist wound environment conducive to healing, while decreasing the chance of infection through its antimicrobial properties. This paper evaluates scar healing after foot or ankle surgery in patients treated with either the standard petroleum-based dressing, or the silver hydrogel sheet dressing. Patients who were treated with the silver hydrogel dressing had less itching and pain, as well as a smaller scar area than patients in the standard dressing group. Therefore, our results suggest that the silver hydrogel dressing may improve scarring after surgery.

A decellularized flowable placental connective tissue matrix supports cellular functions of human tenocytes in vitro.

PURPOSE: Injectable connective tissue matrices (CTMs) may promote tendon healing, given their minimally invasive properties, structural and biochemical extracellular matrix components, and capacity to fill irregular spaces. The purpose of this study is to evaluate the effects of placental CTMs on the cellular activities of human tenocytes. Decellularization, the removal of cells, cell fragments, and DNA from CTMs, has been shown to reduce the host's inflammatory response. Therefore, the authors hypothesize that a decellularized CTM will provide a more cell-friendly matrix to support tenocyte functions. METHODS: Three human placental CTMs were selected for comparison: AmnioFill® (A-CTM), a minimally manipulated, non-viable cellular particulate, BioRenew™ (B-CTM), a liquid matrix, and Interfyl® (I-CTM), a decellularized flowable particulate. Adhesion and proliferation were evaluated using cell viability assays and tenocyte migration using a transwell migration assay. Gene expression of tenocyte markers, cytokines, growth factors, and matrix metalloprotease (MMP) in tenocytes were assessed using quantitative polymerase chain reaction. RESULTS: Although A-CTM supported more tenocyte adhesion, I-CTM promoted significantly more tenocyte proliferation compared with A-CTM and B-CTM. Unlike A-CTM, tenocyte migration was higher in I-CTM than the control. The presence of I-CTM also prevented the loss of tenocyte phenotype, attenuated the expression of pro-inflammatory cytokines, growth factors, and MMP, and promoted the expression of antifibrotic growth factor, TGFß3. CONCLUSION: Compared with A-CTM and B-CTM, I-CTM interacted more favorably with human tenocytes in vitro. I-CTM supported tenocyte proliferation with reduced de-differentiation and attenuation of the inflammatory response, suggesting that I-CTM may support tendon healing and regeneration in vivo.

The Use of Decellularized Human Placenta in Full-Thickness Wound Repair and Periarticular Soft Tissue Reconstruction: An Update on Regenerative Healing.

Prolonged or incomplete healing of the foot and ankle can pose significant challenges. Therefore, investigators have begun searching for alternative treatment strategies. With advances in tissue engineering, decellularized human placental connective tissue matrix has been suggested as a means to achieve more rapid and complete healing for various soft tissue and bone procedures. Basic science and clinical studies have shown that decellularized human placental connective tissue matrix can support regenerative healing through cellular migration, accelerated tissue remodeling, and the establishment of functional tissue. Additional research is needed to fully explore and evaluate clinical applications within the foot and ankle.