Bone tissue engineering aims to develop biomaterials that are capable of effectively repairing and regenerating damaged bone tissue. Among the various polymers used in this field, polycaprolactone (PCL) is one of the most widely utilized. As a biocompatible polymer, PCL is easy to fabricate, cost-effective, and offers consistent quality control, making it a popular choice for biomedical applications. However, PCL lacks inherent antibacterial properties, making it susceptible to bacterial adhesion and biofilm formation, which can lead to implant failure. To address this issue, this study aims to enhance the antibacterial properties of PCL by incorporating calcium phosphate composite (PCL_CaP) nanostructures onto its surface via hydrothermal synthesis. The resulting “PCL_CaP” nanostructured surfaces exhibited improved wettability and demonstrated mechano-bactericidal potential against Escherichia coli and Bacillus subtilis. The flake-like morphology of the fabricated CaP nanostructures effectively disrupted bacteria membranes, inhibiting bacterial growth. Furthermore, the “PCL_CaP” surfaces supported the adhesion, proliferation, and differentiation of pre-osteoblasts, indicating their potential for bone tissue engineering applications. This study demonstrates the promise of calcium phosphate composite nanostructures as an effective antibacterial coating for implants and medical devices, with further research required to evaluate their long-term stability and in vivo performance.

Polycaprolactone (PCL) is one of the most widely used polymers in tissue engineering owing to its excellent biocompatibility, biodegradability, and processability. Nevertheless, most previous studies have primarily employed research-grade PCL, thereby limiting its clinical translation. In this study, four types of medical-grade PCL (RESOMER^® C203, C209, C212, and C217) were systematically evaluated for their applicability in three-dimensional (3D) printing, with respect to printability, mechanical characteristics, chemical stability, and biodegradation behavior. Among these, C209 and C212 exhibited superior printability and mechanical strength. FT-IR analysis showed that the chemical structure of PCL remained unchanged after both 3D printing and E-beam sterilization, while compressive testing demonstrated no significant differences in mechanical characteristics. In vitro degradation assessment revealed a time-dependent decrease in molecular weight. For kinetic analysis, both C209 and C212 were fitted using pseudo-first-order and pseudo-second-order models, which yielded comparable coefficients of determination (R²), suggesting that degradation may be governed by multiple factors rather than a single kinetic pathway. Taken together, these findings indicate that medical-grade PCL, particularly C209 and C212, is highly suitable for 3D printing. Furthermore, this study provides fundamental insights that may facilitate the clinical translation of PCL-based scaffolds for tissue engineering and biomedical implantation.

Esophageal cancer (EC) is the eighth leading cause of cancer-related deaths globally, largely due to its late-stage diagnosis and aggressive progression. Esophagectomy remains the primary treatment, typically requiring organ-based reconstruction techniques such as gastric pull-up or colonic interposition. However, these reconstruction methods often lead to severe complications, significantly reducing the quality of life of patients. To address these limitations, tissue engineering has emerged as a promising alternative, offering bioengineered patch-type and tubular-type scaffolds designed to restore both structural integrity and functional regeneration. Recent advancements in three-dimensional (3D) biofabrication—including 3D bioprinting, electrospinning, and other cutting-edge techniques—have facilitated the development of patient-specific constructs with improved biocompatibility. Despite significant advancements, critical challenges persist in achieving mechanical durability, multilayered cellular organization, and physiological resilience post-transplantation. Ongoing research continues to address these limitations and enhance clinical applicability. Therefore, this review aims to examine recent advancements in esophageal tissue engineering, with a focus on key biofabrication techniques, preclinical animal models, and the major translational challenges that must be addressed for successful clinical application.

Background: Although various surface modifications enhance titanium (Ti) implant osseointegration, achieving rapid bone formation comparable to native healing remains challenging. Current strategies primarily focus on micro-scale topography, often overlooking the critical role of macroscopic three-dimensional (3D) architecture in osteoconduction.Methods: We hypothesized that mimicking native bone’s porous architecture is key to accelerating osseointegration. First, we verified the impact of structural continuity by comparing standard Ti implants with decellularized bone grafts in a mouse calvaria defect model. Subsequently, we developed a biomimetic polycaprolactone (PCL)-based 3D architectural cover (Cover-type) and evaluated its osseointegration efficacy in a rat femur model against conventional Ti implants.Results: The mouse study confirmed that decellularized bone integrated significantly faster than Ti, highlighting the necessity of 3D continuity. In the rat model, micro-computed tomography analysis indicated a clear trend of increased bone formation in the Cover-type group, though statistical significance was limited by sample size. However, histological analysis confirmed a statistically significant enhancement in bone-to-implant contact compared to controls (P<0.05). The PCL structure served as a scaffold for cell migration, effectively bridging the implant-bone gap.Conclusions: These findings suggest that providing a bone-like 3D environment via a PCL cover may enhance histological osseointegration, rather than relying solely on surface chemistry.

Dental implant surgery usually takes over 6 to 9 months, with 3 to 6 months specifically allocated for osseointegration between the implant and the surrounding bone. To expedite this process, we developed an innovative hybrid composite structure and a bioreactor. This hybrid structure features an assembly-type implant combined with a 3D-printed polycaprolactone (PCL) scaffold. The implant was redesigned in a modular format to enable the insertion of a scaffold between components, facilitating bone-to-bone contact instead of metal-to-bone contact, which enhances osseointegration. The PCL scaffold was coated with polydopamine (PDA) to improve cell adhesion. Additionally, a bioink that mimics bone composition, consisting of type I collagen and nano-hydroxyapatite (nHA), was incorporated into the scaffold. To support cell maturation within the scaffold, we developed a hydrostatic pressure bioreactor system that applies uniform compressive stress to complex 3D structures. We assessed cell viability in the scaffold using the CCK-8 assay, and SEM imaging confirmed the effectiveness of the PDA coating. Furthermore, we evaluated osteogenic differentiation through ALP activity and calcium quantification assays under both static and dynamic stimulation conditions.