Comparative study of the bioactive PLGA/CaP composites: the influence of 3D structure on inflammatory and osteoinductive properties

3D-Printed PLA/MgO/UCNPs composite scaffolds for immunomodulation and osteogenic bone repair.

The persistent inflammatory microenvironment during bone defect repair can inhibit osteogenic differentiation, delay angiogenesis, and reduce the reparative efficacy of implanted materials. Therefore, developing biomaterials that combine immunomodulatory functions with bone-regenerative capacity is of great significance. In this study, composite scaffolds with anti-inflammatory and bone-repair-promoting properties were fabricated through surface functionalization and 3D printing. The structural and physicochemical properties of the scaffolds were systematically characterized by scanning electron microscopy (SEM), elemental mapping, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), contact angle measurement, and mechanical testing. Transmission electron microscopy and related analyses were further used to evaluate their microstructure and surface characteristics. The degradation behavior, pH variation, ion release profile, and antioxidant performance of the scaffolds under inflammatory conditions were then investigated to verify their ability to regulate the local microenvironment. In vitro, cytocompatibility was evaluated using CCK-8 assays, live/dead staining, and immunofluorescence staining. The effects of the scaffolds on macrophage polarization and inflammatory factor expression were further analyzed. Their osteogenic differentiation potential was assessed by alkaline phosphatase (ALP) staining, Alizarin Red staining, and osteogenesis-related gene expression analysis. In addition, Micro-CT, hematoxylin and eosin (HE) staining, and Masson's trichrome staining were performed in a bone defect animal model to evaluate bone regeneration and tissue repair. The results showed that the composite scaffolds effectively improved the inflammatory microenvironment in the defect region, promoted macrophage polarization toward an anti-inflammatory phenotype, enhanced cellular osteogenic activity and mineralization, and facilitated new bone formation and tissue reconstruction. This study provides a theoretical basis and experimental evidence for the design and application of bone repair materials under inflammatory conditions.

HAp/PLGA/Chitosan Scaffolds Fabricated by Freeze-Drying and 3D Printing for Bone Regeneration: In Vitro Evaluation and Finite Element Analysis

Tooth loss and bone resorption of the alveolar cavity caused by dental caries and periodontal disease remain major clinical challenges that compromise oral function. Tissue engineering approaches based on biocompatible scaffolds have emerged as promising strategies for bone regeneration; however, the influence of fabrication methods on scaffold performance remains unclear. This study developed hydroxyapatite/poly (lactic-coglycolic acid)/chitosan scaffolds (HAp/PLGA/CS) using freeze-drying and 3D-printing techniques and evaluated their physicochemical, biological, and biomechanical properties. The morphology, porosity, elemental composition, and mechanical properties of the scaffold were characterized, while the biocompatibility and osteogenic potential were evaluated using human dental pulp stem cells (hDPSCs). Finite element analysis (FEA) using COMSOL Multiphysics® Version 6.2. was performed to evaluate scaffold behavior under simulated dental implant loading conditions. The 3D-printed scaffolds exhibited significantly higher cell viability than the freeze-dried scaffolds, reaching approximately 85% in the 50% filling group compared with 50% in the freeze-dried group. Microstructural analysis revealed interconnected hierarchical porosity, including macro-, micro-, and submicrometer scale pores. Although the 50% infill scaffold showed the highest cell viability, the 70% infill scaffold demonstrated the most favorable osteogenic profile, with enhanced expression of RUNX2 and OSX. Both types exhibited degradation profiles compatible with early bone regeneration. FEA simulations indicated that further mechanical optimization is required to improve load transfer and reduce deformation at the implant–scaffold interface. Overall, HAp/PLGA/CS scaffolds showed potential as experimental bioactive platforms for bone tissue engineering, with 3D-printed scaffolds providing greater architectural control and favorable early osteogenic responses. However, the translational relevance of these findings remains preliminary and requires validation through long-term degradation studies, in vivo bone regeneration and osseointegration models, cyclic mechanical testing, and implant fixation experiments.

Characterisation and In Vitro Biocompatability of Polycaprolactone: Cissus Quandrangularis Electrospun Scaffold for Bone Regeneration

The aim of the present study is to develop an osteogenic bone graft material with an herbal component. Cissus quadrangularis, a perennial climber widely used in traditional Indian is reported to possess bone fracture healing activity. Polycaprolactone (PCL) an FDA approved biocompatible polymer and Cissus Quadrangularis (CQ) were blend and electrospun to obtain a nanofibrous scaffold. The fiber morphology was characterised by scanning electron microscopy, FT-IR, XRD and TGA. MG63 osteoblast-like cells were used to evaluate the biocompatibility using MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The in-vitro experiment revealed that the PCL-CQ composite electrospun scaffold showed better MG63 cell adhesion and growth compared to the control PCL scaffold and thus could be a potential scaffold material for bone defect applications.

Electrospun Chitosan/Collagen Fibers Incorporating PLGA and Hydroxyapatite Nanoparticles for In-Vitro 3T3 Fibroblast Migration

The development of 3D scaffolds that enable the reliable evaluation of cell migration remains a critical challenge in tissue engineering and wound-healing-related research. In this work, 3D scaffolds based on Chitosan/Collagen/Poly(lactic-co-glycolic acid) (PLGA)/Hydroxyapatite (HAp) nanoparticles are presented as a promising approach to studying the migration of the 3T3 cell line. The electrospinning technique was employed to fabricate fibers with an average diameter of 0.2 μm for CH/Coll, 0.69 μm for CH/Coll/PLGA, and 0.14 μm for CH/Coll/HAp. The electrospinning parameters were optimized, and the properties of the scaffolds were further enhanced by incorporating hydroxyapatite (HAp) and PLGA, thereby improving their regenerative potential and tissue-engineering applicability. Preliminary cell proliferation was monitored in the wound area at 4, 12, 24, and 35 h. The highest cell migration was observed in scaffolds with hydroxyapatite nanoparticles. The resulting fiber matrix demonstrated promising effects on fibroblast migration in an in vitro scratch-assay model using NIH 3T3 cells, relevant to skin tissue repair.

The Influence of Copolymer Composition on PLGA/nHA Scaffolds’ Cytotoxicity and In Vitro Degradation

Development and biological validation of a dexamethasone-loaded, PLA-based 3D-printable composite filament for bone tissue engineering

Critical-sized bone defects remain a major therapeutic challenge. Among additive manufacturing approaches, fused filament fabrication provides a scalable alternative to autografting by enabling the production of patient-specific scaffolds with integrated bioactive functionality. Given the osteogenic and immunomodulatory properties of dexamethasone (DEXA), this study aimed to develop a 3D-printable DEXA-loaded polylactic acid (PLA) composite filament for controlled local drug delivery and to assess its osteogenic and immunomodulatory effects in vitro. DEXA–PLA composite filaments (0.1% and 1% w/w) were fabricated by melt extrusion. Thermal, chemical, surface, and mechanical characterization were performed using thermogravimetric analysis, differential scanning calorimetry, dynamic mechanical analysis, Fourier-transform infrared spectroscopy, contact angle, and three-point bending tests. DEXA release over 28 days was quantified by ELISA. Human mesenchymal stromal cells (MSCs) or THP-1–derived macrophages (TDM) were cultured in indirect contact with PLA or DEXA–PLA (0.1% or 1%) test specimens or treated with soluble DEXA as positive control. Osteogenic and immunomodulatory effects were assessed by metabolic activity (resazurin assay), gene expression (RT-qPCR), extracellular matrix (ECM) mineralization (Alizarin Red quantification), and cytokine secretion (Cytometric Bead Array). Statistical analysis was performed using two-way ANOVA followed by Tukey’s multiple comparisons test, and Kruskal–Wallis/Dunn (n = 4; α = 0.05). Thermal, chemical, surface, and mechanical properties of CF are largely preserved after DEXA incorporation. Both formulations exhibited distinct, concentration-dependent release kinetics. While the 0.1% DEXA–PLA showed a transient increase in DEXA concentration up to 72 h followed by decline, the 1% DEXA–PLA established a sustained plateau (~143 ng of DEXA per g of test specimen) over 28 days. Neither composite affected MSC metabolic activity. After 14 days, the 1% DEXA–PLA significantly enhanced ALPL expression and ECM mineralization compared with the 0.1% DEXA–PLA and PLA, reaching levels comparable to osteogenic differentiation medium (10 nM DEXA). In macrophages, the 1% DEXA–PLA selectively reduced in M1 cells metabolic activity, IL1B expression and secretion of IL-1β, IL-6, and TNF-α, while upregulating CD163 and PPARG. The FFF-compatible 1% DEXA–PLA CF retains physicochemical integrity after DEXA incorporation and enables sustained local DEXA delivery within a biologically active concentration range, achieving dual osteogenic and immunomodulatory effects, as evidenced by attenuated M1 macrophage activation. These findings demonstrate the feasibility of integrating DEXA into a controlled drug release system for bone tissue engineering applications.