Acellular dermal matrices (ADM) are a suitable alternative to autogenous soft tissue grafts (ASG). The aim of this study was to analyze the biomechanical properties and architectural features of AS...

Background: The aim of this study was to analyze possible interactions of different xenogeneic collagen membranes (CM) and platelet-rich fibrin (PRF). PH values were evaluated in the CM rehydration process with PRF, and their influence on angiogenesis was analyzed in vivo. Materials and Methods: Porcine (Bio-Gide^®, Geistlich)- and bovine-derived collagen membranes (Symbios^®, Dentsply Sirona) were biofunctionalized with PRF by plotting process. PRF in comparison to blood, saline and a puffer pH7 solution was analysed for pH-value changes in CM rehydration process in vitro. The yolk sac membrane (YSM) model was used to investigate pro-angiogenic effects of the combination of PRF and the respective CM in comparison to native pendant by vessel in-growth and branching points after 24, 48 and 72 h evaluated light-microscopically and by immunohistochemical staining (CD105, αSMA) in vivo. Results: Significantly higher pH values were found at all points in time in PRF alone and its combined variants with Bio-Gide^® and Symbios^® compared with pure native saline solution and pH 7 solution, as well as saline with Symbios^® and Bio-Gide^® (each p < 0.01). In the YSM, vessel number and branching points showed no significant differences at 24 and 48 h between all groups (each p > 0.05). For PRF alone, a significantly increased vessel number and branching points between 24 and 48 h (each p < 0.05) and between 24 and 72 h (each p < 0.05) was shown. After 72 h, CM in combination with PRF induced a statistically significant addition to vessels and branching points in comparison with native YSM (p < 0.01) but not vs. its native pendants (p > 0.05). Summary: PRF represents a promising alternative for CM rehydration to enhance CM vascularization.

Objectives: Pre-vascularization of the collagen membranes with autologous platelet concentrates is a standard procedure in oral and maxillofacial surgery. This study analyzed the possible interaction of an acellular collagen membrane of porcine origin (NM) with platelet-rich fibrin (PRF) regarding its rehydration protocol with differences in pH values and effect on angiogenesis. Materials and methods: NM was analyzed alone and combined with solid PRF by plotting or co-culturing with injectable PRF. Different media (venous blood, buffer solution with a fixed pH value of 7, saline solution, and injectable PRF) were used to analyze the influence on pH value during rehydration. Chorion allantois membrane assay (CAM) was applied to check pro-angiogenic effects after 24, 48, and 72 h, followed by immunohistochemical analysis. Results: Rehydration in injectable PRF showed acidity over time (p < 0.05). A definite pro-angiogenic effect of NM alone was found regarding neo-vessel formation supported by the respective light microscopically analysis without significant differences to PRF alone (p > 0.005). This pro-angiogenic effect could not be exaggerated when NM was combined with liquid/solid PRF (each p > 0.005). Conclusions: Rehydration with liquid PRF of the collagen membrane results in acidity compared to a saline solution or patient’s blood. The significant pro-angiogenic potential of the membrane alone resulted in enhanced neo-vessel formation that could not be optimized with the addition of PRF. Clinical relevance statement: Using injectable PRF for rehydration protocol of the collagen membrane leads to acidosis that can ultimately optimize wound healing. Differences in the physio-mechanical interplay of collagen matrices and autologous platelet concentrates must result in clinical algorithms if pre-vascularization can maximize outcomes.

Purpose: Biocompatible collagen membranes (CM) are widely used in regenerative dentistry, particularly in guided tissue regeneration (GTR) and guided bone regeneration (GBR). While resorbable CMs offer advantages such as reduced patient morbidity and enhanced wound healing, their barrier function can impede vascularization, potentially compromising graft survival. Biofunctionalization of CMs with platelet-rich fibrin (PRF) and hyaluronic acid (HA) has shown promise in enhancing angiogenesis. This experimental study evaluates the pro-angiogenic effects of biofunctionalizing collagen membranes with advanced PRF (A-PRF), injectable PRF (i-PRF), and HA using the chorioallantoic membrane (CAM) assay in ovo. Methods: Three porcine-derived collagen membranes (Mucoderm®, Bio-Gide®, and Smartbrane®) were biofunctionalized with A-PRF, i-PRF, or HA and applied to the CAM assay on day 7 of incubation. Afterwards, two experimental series were evaluated. The first series investigated Mucoderm (MM native, A-PRF, and MM combined with A-PRF) over an observation period ranging from 24 to 120 h ( N = 135). The second series examined Bio-Gide® and Smartbrane (BM native, BM combined with i-PRF, BM combined with HA, and SM combined with HA) over a period from 24 to 72 h ( N = 60). To assess impact on angiogenesis, vascularization was evaluated at multiple time points (24 h, 48 h, 72 h, 96 h, and 120 h) using immunohistochemical staining (hematoxylin-eosin, α-smooth muscle actin, CD105) and artificial intelligence (AI)-assisted image analysis (IKOSA® software). Results: Biofunctionalization of Mucoderm® with A-PRF significantly enhanced angiogenesis up to 96 h, as evidenced by increased vessel area, length, and branching points ( p < 0.05). I-PRF biofunctionalization of Bio-Gide® also promoted angiogenesis between 24 h ( p = 0.036) and 72 h, showing significantly improved values for total area ( p = 0.007), vessel length ( p = 0.018), and vessel thickness ( p = 0.008) compared with the native membrane. While HA biofunctionalization of Bio-Gide® and Smartbrane® resulted in significantly increased angiogenesis at 48 and 72 h ( p < 0.05), its effects were less pronounced than those achieved with PRF variants. Native Bio-Gide® exhibited greater pro-angiogenic potential than native Mucoderm® at 24 h ( p = 0.012); however, biofunctionalized membranes generally outperformed native variants. Conclusions: Biofunctionalization of collagen membranes with A-PRF and i-PRF significantly enhances angiogenesis in ovo, with A-PRF showing sustained effects up to 96 h. HA also promotes angiogenesis and represents a viable, cost-effective alternative that does not require blood collection. Both PRF and HA biofunctionalization may offer potential benefits for enhancing vascularization in GBR/GTR applications. However, their pro-angiogenic potential and clinical relevance remain exploratory at this stage for pourely in-ovo results. The study is limited to an in-ovo setting, therefore the transferability to oral soft tissue and bone conditions is restricted. Further randomized clinical studies are needed to better understand and evaluate the possible advantages.

Objectives Pre-Vascularization of collagen membranes with autologous platelet concentrates is a standard procedure in oral and maxillofacial surgery. This study analyzed the possible interaction of an acellular collagen membrane of porcine origin (NM) with platelet-rich fibrin (PRF) regarding its rehydration protocol with differences in pH values and effect on angiogenesis. Materials and methods NM was analyzed alone and combined with solid PRF by plotting or co-culturing with injectable PRF. Different media (venous blood, buffer solution with a fixed pH value of 7, saline solution, and injectable PRF) were used to analyze the influence on pH value during rehydration. Chorion allantois membrane assay (CAM) was applied to check pro-angiogenic effects after 24, 48, and 72 hours, followed by immunohistochemical analysis. Results Rehydration in injectable PRF showed acidity over time (p < 0.05). A definite pro-angiogenic effect of NM alone was found regarding neo-vessel formation supported by the respective light microscopically analysis without significant differences to PRF alone (p>0.005). This pro-angiogenic effect could not be exaggerated when NM was combined with liquid/solid PRF (each p>0.005). Conclusions Rehydration with liquid PRF of the collagen membrane results in acidity compared to a saline solution or patient’s blood. The significant pro-angiogenic potential of the membrane alone resulted in enhanced neo-vessel formation that could not be optimized with the addition of PRF.