The skin protects the body from external barriers. Certain limitations exist in the development of technologies to rapidly prepare skin substitutes that are therapeutically effective in surgeries involving extensive burns and skin transplantation. Herein, we fabricated a structure similar to the skin layer by using skin-derived decellularized extracellular matrix (dECM) with bioink, keratinocytes, and fibroblasts using 3D-printing technology. The therapeutic effects of the produced skin were analyzed using a chimney model that mimicked the human wound-healing process. The 3D-printed skin substitutes exhibited rapid re-epithelialization and superior tissue regeneration effects compared to the control group. These results are expected to aid the development of technologies that can provide customized skin-replacement tissues produced easily and quickly via 3D-printing technology to patients.

The effectiveness of small-diameter vascular grafts depends on their antithrombogenic properties and ability to undergo accelerated endothelialization. The extreme hydrophobic nature of poly(ε-caprolactone) (PCL) hinders vascular tissue integration, limiting its use in medical implants. To enhance the antithrombogenicity of PCL as a biomaterial, we grafted 2-aminoethyl methacrylate (AEMA) hydrochloride onto the PCL surface using gamma irradiation; developed a biodegradable heparin-immobilized PCL nanofibrous scaffold using gamma irradiation and N-(3-dimethylaminopropyl)-N′-ethyl carbodiimide hydrochloride/N-hydroxysuccinimide reaction chemistry; and incorporated vascular endothelial growth factor (VEGF) into the scaffold to promote vascular endothelial cell proliferation and prevent thrombosis on the vascular grafts. We assessed the physicochemical properties of PCL, heparin-AEMA-PCL (H-PCL), and VEGF-loaded heparin-AEMA-PCL (VH-PCL) vascular grafts using scanning electron microscopy, attenuated total reflection–Fourier transform infrared spectroscopy, toluidine blue O staining, and fibrinogen adsorption and surface wettability measurement. In addition, we implanted the vascular grafts into 24-month-old Sprague Dawley rats and evaluated them for 3 months. The H-PCL and VH-PCL vascular grafts improved the recovery of blood vessel function by promoting the proliferation of endothelial cells and preventing thrombosis in clinical and histological evaluation, indicating their potential to serve as functional vascular grafts in vascular tissue engineering.

Background/Aim: Oral lesions are a common clinical symptom that can impair the quality of life of patients. Several treatments have been developed; however, therapies for wounds on the oral mucosa are symptomatic and unsatisfactory. This study aimed to evaluate the efficacy of an oral wound dressing (OWD) film in healing excision and chemical burns using a rabbit oral wound model and to demonstrate the effect of physical barriers during wound healing. Materials and Methods: Excision and chemical burn wounds were induced on the oral hard palate of animals. Four experimental groups were established. The OWD film was applied immediately after surgery and replaced every 24 h over the following 3 days. The animals were sacrificed at 3, 7, and 14 days after surgery. The hard palate tissues were analyzed by histological and immunohistochemical evaluation. The degree of epithelialization, number of proliferating cells, and collagen deposition were evaluated. Statistical significance was analyzed using the Student’s t-test. Results: Following application of the OWD film to the excision and chemical burn wounds, the OWD treatment group’s epithelial gap and proliferation showed a significant difference compared to those of the untreated group during the proliferative stage of wound healing. However, there was no difference in the epithelial gap in the chemical burn wound model, whereas the OWD treatment group showed a significantly reduced ulcerated area. Collagen deposition in the OWD treatment group was significantly increased during the remodeling stage of wound healing. Conclusion: The OWD film treatment promoted wound healing in the oral mucosa by accelerating wound closure and reconstruction.

Introduction: Tooth fracture is one of the most common traumatic maxillofacial injuries in dogs and cats. For fractures with pulp exposure occurring in functionally important teeth, the literature indicates that root canal treatment (RCT) is an effective therapy option that may be the remedy of choice before extraction. The most commonly reported fractures in the United States involve canine teeth; however, fractures of the maxillary fourth premolars are more common in Korea, where there are many small-and medium-sized dogs. RCT mechanically and chemically removes pulp tissue and bacteria (cleaning and shaping) from the infected root canal, and obturates the root canal with filling material to restore tooth functionality without inflammation. Various techniques, instruments, and materials used in humans have been modified for application in veterinary dentistry.Methods: This study analyzed the results of RCT of the maxillary fourth premolar in 120 small-and medium-sized dogs (weighing less than 25 kg) using three different sealers (silicone-based sealer, bioceramic sealer, and calcium hydroxide-based sealer) through a simple application of the single-cone technique.Results: The overall success rate of RCT in maxillary fourth premolars was 90.83%, with 8.33% no evidence of failure (NEF) and 0.83% failure.Discussion: There were no significant differences between the three different sealers. Furthermore, preexisting periapical lesion (PAL) was reconfirmed as a factor in reducing the success rate of RCT. In addition, the working length and master apical file of each root were analyzed in our study as a novel reference for endodontic veterinarians.

Background: Mesenchymal stem cells (MSCs) offer a promising avenue for cartilage regeneration; however, their therapeutic efficacy requires substantial improvement. Cell priming using electrical stimulation (ES) is a promising approach to augmenting the therapeutic potential of MSCs and has shown potential for various regenerative applications. This study aimed to promote the ES-mediated chondrogenic differentiation of human MSCs and facilitate the repair of injured articular cartilage. Methods: MSCs were subjected to ES under various conditions (e.g., voltage, frequency, and number of repetitions) to enhance their capability of chondrogenesis and cartilage regeneration. Chondrogenic differentiation of electrically primed MSCs (epMSCs) was assessed based on gene expression and sulfated glycosaminoglycan production, and epMSCs with hyaluronic acid were transplanted into a rat osteochondral defect model. Transcriptomic analysis was performed to determine changes in gene expression by ES. Results: epMSCs exhibited significantly increased chondrogenic gene expression and sulfated glycosaminoglycan production compared with those in unstimulated controls. Macroscopic and histological results showed that in vivo epMSC transplantation considerably enhanced cartilage regeneration. Furthermore, ES markedly altered the expression of numerous genes of MSCs, including those associated with the extracellular matrix, the Wnt signaling pathway, and cartilage development. Conclusion: ES can effectively prime MSCs to improve articular cartilage repair, offering a promising strategy for enhancing the efficacy of various MSC-based therapies.

Background/Aim: Dural reconstruction is a critical process after neurosurgical procedures. Improper dural repair leads to serious side-effects, such as cerebrospinal fluid leakage or infection. This is why it is important to properly repair the dura using a dural substitute, and research into dural substitutes is ongoing. The ideal dural substitute should be non-toxic, biocompatible, and capable of maintaining adequate tension and preventing cerebrospinal fluid leakage for extended periods in vivo. This study evaluated the biocompatibility and healing properties of Safe-Seal, poly-L-lactic acid synthetic bioabsorbable dural substitute produced by electrospinning technology. Materials and Methods: Safe-Seal, was created by electrospinning, which is a technique for nanofiberizing polymers into three-dimensional structures, and its cytotoxicity was evaluated. The animal study used 30 rats, divided into three groups assessed at two time points (4 and 12 weeks). The study groups were a negative control group with no treatment, an experimental group with Safe-Seal (TDM Co. Ltd., Gwangju, Republic of Korea) implantation, and a positive control group with a commercial product, Redura^® (Medprin Biotech, Frankfurt, Germany) implantation. Results: Safe-Seal exhibited no cytotoxic or adverse effects in the in vivo animal study. Histologically, Safe-Seal displayed less inflammatory cell infiltration, less adhesion to brain tissue, and connectivity with the surrounding dura mater as compared to the negative control group and without any significant differences from Redura^® in all evaluation criteria. Conclusion: Safe-Seal presented adequate biocompatibility in vivo and contributed to the healing of the dura mater at a similar level to that of Redura^® when applied to dural defects.