Programmable Electro-Assembly of Collagen: Constructing Porous Janus Films with Customized Dual Signals for Immunomodulation and Tissue Regeneration in Periodontitis Treatment.

Currently available guided bone regeneration (GBR) films lack active immunomodulation and sufficient osteogenic ability- in the treatment of periodontitis, leading to unsatisfactory treatment outcomes. Challenges remain in developing simple, rapid, and programmable manufacturing methods for constructing bioactive GBR films with tailored biofunctional compositions and microstructures. Herein, the controlled electroassembly of collagen under the salt effect is reported, which enables the construction of porous films with precisely tunable porous structures (i.e., porosity and pore size). In particular, bioactive salt species such as the anti-inflammatory drug diclofenac sodium (DS) can induce and customize porous structures while enabling the loading of bioactive salts and their gradual release. Sequential electro-assembly under pre-programmed salt conditions enables the manufacture of a Janus composite film with a dense and DS-containing porous layer capable of multiple functions in periodontitis treatment, which provides mechanical support, guides fibrous tissue growth, and acts as a barrier preventing its penetration into bone defects. The DS-containing porous layer delivers dual bio-signals through its morphology and the released DS, inhibiting inflammation and promoting osteogenesis. Overall, this study demonstrates the potential of electrofabrication as a customized manufacturing platform for the programmable assembly of collagen for tailored functions to adapt to specific needs in regenerative medicine.

Avastin-Loaded 3D-Printed Alginate Scaffold as an Effective Antiadhesive Barrier to Prevent Postsurgical Adhesion Bands Formation.

Postoperative adhesion can cause complications, such as pain and organ blockage, in the abdominal regions. To address this issue, surgical techniques and antiadhesive treatments are applied. Given the significant role of vascularization in adhesion band formation, Avastin (Ava) that targets vascular endothelial growth factor (VEGF) can be applied to prevent peritoneal adhesion bands. Moreover, Alginate (Alg), a natural polysaccharide, is a promising physical barrier to prevent adhesion bands. Incorporating Ava into Alg hydrogel in a form of 3D-printed scaffold (Alg/Ava) has potential to suppress inflammation and angiogenesis, leading to reduce peritoneal adhesion bands. Following physical, morphological, and biocompatibility evaluations, the efficacy of Alg and Ava alone and their combination in Alg/Ava on the formation of postsurgical adhesions is evaluated. Upon confirming physical stability and sustained release of Ava, the Alg/Ava scaffold effectively diminishes both the extent and strength of adhesion bands. Histopathological examination shows that the reduction in fibrosis and inflammation is responsible for preventing adhesion bands by the Alg/Ava scaffold. Additionally, the cytokine assessment reveals that this is due to the inhibition in the secretion of VEGF and Interleukin 6 suppressing vascularization and inflammatory pathways. This study suggests that a 3D-printed Alg/Ava scaffold has great potential to prevent the postsurgical adhesion bands.

Three-dimensional printing bilayer membranous nanofiber scaffold for inhibiting scar hyperplasia of skin.

Hypertrophic scar (HS) is the manifestation of pathological wound healing, which affects the beauty of patients, and even affects the normal physical functions of patients. We aimed to develop a 3D printing layer membranous nanofiber scaffold similar to skin structure. Among them, poly (lactic-co-glycolic acid) copolymer (PLGA) nanofibers were used as the "epidermis" layer above, and a decellular dermis matrix (dECM) nanofiber scaffold was used as the "dermis" layer below. In vitro, experimental results showed that PLGA and dECM nanofiber scaffolds had good biocompatibility. In vivo experiments showed that BLM nanofiber scaffolds could inhibit collagen fiber deposition and angiogenesis, to inhibit the formation of hypertrophic scars. This study shows a simple and effective method for preventing and inhibiting the formation of hypertrophic scars.

Histopathologic and physiologic effect of bifurcation stenting: current status and future prospects.

Introduction: Coronary bifurcation lesions are involved in up to 20% of all percutaneous coronary interventions (PCI). However, bifurcation lesion intervention is associated with a high complication rate, and optimal treatment of coronary bifurcation is an ongoing debate.Areas covered: Both different stenting techniques and a variety of devices have been suggested for bifurcation treatment, including the use of conventional coronary stents, bioresorbable vascular scaffolds (BVS), drug-eluting balloons (DEB), and stents dedicated to bifurcations. This review will summarize different therapeutic approaches with their advantages and shortcomings, with special emphasis on histopathologic and physiologic effects of each treatment strategy.Expert opinion: Histopathology and clinical data have shown that a more simple treatment strategy is beneficial in bifurcation lesions, achieving superior results. Bifurcation interventions through balloon angioplasty or placement of stents can importantly alter the bifurcation's geometry and accordingly modify local flow conditions. Computational fluid dynamics (CFD) studies have shown that the outcome of bifurcation interventions is governed by local hemodynamic shear conditions. Minimizing detrimental flow conditions as much as possible should be the ultimate strategy to achieve long-term success of bifurcation interventions.

Antifibrotic strategies for medical devices.

A broad range of medical devices initiate an immune reaction known as the foreign body response (FBR) upon implantation. Here, collagen deposition at the surface of the implant occurs as a result of the FBR, ultimately leading to fibrous encapsulation and, in many cases, reduced function or failure of the device. Despite significant efforts, the prevention of fibrotic encapsulation has not been realized at this point in time. However, many next-generation medical technologies including cellular therapies, sensors and devices depend on the ability to modulate and control the FBR. For these technologies to become viable, significant advances must be made in understanding the underlying mechanism of this response as well as in the methods modulating this response. In this review, we highlight recent advances in the development of materials and coatings providing a reduced FBR and emphasize key characteristics of high-performing approaches. We also provide a detailed overview of the state-of-the-art in strategies relying on controlled drug release, the surface display of bioactive signals, materials-based approaches, and combinations of these approaches. Finally, we offer perspectives on future directions in this field.

Stress Urinary Incontinence and Pelvic Organ Prolapse: Biologic Graft Materials Revisited.

Symptomatic stress urinary incontinence (SUI) and pelvic organ prolapse (POP) refractory to conservative management with pelvic floor muscle training or vaginal pessaries may warrant surgical intervention with different forms of biologic or synthetic material. However, in recent years, several global regulatory agencies have issued health warnings and recalled several mesh products due to an increase in complications such as mesh erosion, infection, chronic pain, and perioperative bleeding. At present, current surgical treatment strategies for SUI and POP are aimed at developing biological graft materials with similar mechanical properties to established synthetic meshes, but with improved tissue integration and minimal host response. This narrative review aims to highlight recent studies related to the development of biomimetic and biologic graft materials as alternatives to traditional synthetic materials for SUI/POP repair in female patients. We also investigate complications and technical limitations associated with synthetic mesh and biological biomaterials in conventional SUI and POP surgery. Our findings demonstrate that newly developed biologic grafts have a lower incidence of adverse events compared to synthetic biomaterials. However there remains a significant disparity between success in preclinical trials and long-term clinical translation. Further characterization on the optimal structural, integrative, and mechanical properties of biological grafts is required before they can be reliably introduced into clinical practice for SUI and POP surgery. Impact statement Our review article aims to outline the clinical history of developments and controversies associated with the use of synthetic mesh materials in the surgical treatment of stress urinary incontinence and pelvic organ prolapse, as well as highlighting recent advancements in the area of biological graft materials and their potential importance in an area that remains an enduring issue for patients and clinicians alike. This article aims to provide a concise summary of previous controversies in the field of urinary incontinence, while evaluating the future of potential biomaterials in this field.

Three-dimensional evaluation of bone changes following ridge preservation procedures.

PURPOSE: To evaluate three-dimensionally the bone change following ridge preservation procedures (RPP) using computed tomography (CT). MATERIALS AND METHODS: Subjects in need of implant therapy were enrolled in the study. The teeth were extracted, and sockets underwent RPP with a bioactive glass (Inion BioRestore, Inion Oy). The patients were scanned with CT within 1 week and 3 months after surgery. Horizontal and vertical radiographic measurements were performed on superimposed CT scans to evaluate bone changes in the alveolar sites during the 3-month period. RESULTS: Thirteen subjects participated, and 32 teeth were extracted and treated with grafting. Alveolar sites treated with RPP demonstrated a preservation of about 77% of the original width dimensions, with a mean loss of 1.8 ± 1.1 mm in width. Moreover, it was observed that the vertical loss of buccal bone was 2.7 ± 1.1 mm, while the loss of lingual bone was 1.9 ± 1.2 mm. CONCLUSIONS: The CT evaluation was helpful to assess that the bone loss in width was less than the vertical bone loss of both walls 3 months after RPP.

An analysis of bone regeneration at a segmental bone defect by controlled release of bone morphogenetic protein 2 from a biodegradable sponge composed of gelatin and ß-tricalcium phosphate.

To treat large bone defects is a clinically challenging problem and utilizing tissue engineering technology is an attractive approach for overcoming such a problem. Previously, a biodegradable sponge incorporating bone morphogenic protein-2 (BMP-2), which can control the release of BMP-2 for a prolonged time in an in vivo environment, was reported. In addition, a biodegradable sponge composed of gelatin and ß-tricalcium phosphate (ßTCP), gelatin-ßTCP sponge to develop a more ideal scaffold for enhancing bone regeneration was also created and previously reported. The purpose of this study was to investigate the effectiveness of the gelatin-ßTCP sponge for the promotion of bone regeneration in a critical-sized bone defect site in vivo. Apparent bone regeneration was induced by the gelatin sponge incorporating BMP-2 and the gelatin-ßTCP sponge with BMP-2 incorporation. In contrast, no apparent bone formation was induced by either the gelatin sponge only or the gelatin-ßTCP sponge without BMP-2. To investigate the quality of the regenerated bone, we conducted a biomechanical evaluation with a three-point bending test. We found no significant difference between the gelatin sponge incorporating BMP-2 and the gelatin-ßTCP sponge incorporating BMP-2 groups. Incorporation of ßTCP into the gelatin sponge was expected to enhance biomechanical strength during the initial bone regeneration. However, our observations showed that the gelatin-ßTCP sponge did not significantly improve the quality of regenerated bone from the viewpoint of biomechanical assessment, even though it did not impair the effectiveness of the promotion of bone regeneration by BMP-2 in the bone defect.

Effects of epicatechin, a crosslinking agent, on human dental pulp cells cultured in collagen scaffolds

ABSTRACT Objective The purpose of this study was to investigate the biological effects of epicatechin (ECN), a crosslinking agent, on human dental pulp cells (hDPCs) cultured in collagen scaffolds. Material and Method To evaluate the effects of ECN on the proliferation of hDPCs, cell counting was performed using optical and fluorescent microscopy. Measurements of alkaline phosphatase (ALP) activity, alizarin red staining, and real-time polymerase chain reactions were performed to assess odontogenic differentiation. The compressive strength and setting time of collagen scaffolds containing ECN were measured. Differential scanning calorimetry was performed to analyze the thermal behavior of collagen in the presence of ECN. Results Epicatechin increased ALP activity, mineralized nodule formation, and the mRNA expression of dentin sialophosphoprotein (DSPP), a specific odontogenic-related marker. Furthermore, ECN upregulated the expression of DSPP in hDPCs cultured in collagen scaffolds. Epicatechin activated the extracellular signal-regulated kinase (ERK) and the treatment with an ERK inhibitor (U0126) blocked the expression of DSPP. The compressive strength was increased and the setting time was shortened in a dose-dependent manner. The number of cells cultured in the ECN-treated collagen scaffolds was significantly increased compared to the cells in the untreated control group. Conclusions Our results revealed that ECN promoted the proliferation and differentiation of hDPCs. Furthermore, the differentiation was regulated by the ERK signaling pathway. Changes in mechanical properties are related to cell fate, including proliferation and differentiation. Therefore, our study suggests the ECN treatment might be desirable for dentin-pulp complex regeneration.