Design and development of poly-L/D-lactide copolymer and barium titanate nanoparticle 3D composite scaffolds using breath figure method for tissue engineering applications

In tissue engineering, the scaffold topography influences the adhesion, proliferation, and function of cells. Specifically, the interconnected porosity is crucial for cell migration and nutrient delivery in 3D scaffolds. The objective of this study was to develop a 3D porous composite scaffold for musculoskeletal tissue engineering applications by incorporating barium titanate nanoparticles (BTNPs) into a poly-L/D-lactide copolymer (PLDLA) scaffold using the breath figure method. The porous scaffold fabrication utilised 96/04 PLDLA, dioleoyl phosphatidylethanolamine (DOPE), and different types of BTNPs, including uncoated BTNPs, Al2O3-coated BTNPs, and SiO2-coated BTNPs. The BTNPs were incorporated into the polymer scaffold, which was subsequently analysed using field emission scanning electron microscopy (FE-SEM). The biocompatibility of each scaffold was tested using ovine bone marrow stromal stem cells. The cell morphology, viability, and proliferation were evaluated using FE-SEM, LIVE/DEAD staining, and Prestoblue assay. Porous 3D composite scaffolds were successfully produced, and it was observed that the incorporation of uncoated BTNPs increased the average pore size from 1.6 mu m (PLDLA) to 16.2 mu m (PLDLA/BTNP). The increased pore size in the PLDLA/BTNP scaffolds provided a suitable porosity for the cells to migrate inside the scaffold, while in the pure PLDLA scaffolds with their much smaller pore size, cells elongated on the surface. To conclude, the breath figure method was successfully used to develop a PLDLA/BTNP scaffold. The use of uncoated BTNPs resulted in a composite scaffold with an optimal pore size while maintaining the honeycomb-like structure. The composite scaffolds were biocompatible and yielded promising structures for future tissue engineering applications.Peer reviewe

Three-dimensional microstructure of human meniscus posterior horn in health and osteoarthritis

Abstract Objective: To develop and perform ex vivo 3D imaging of meniscus posterior horn microstructure using micro-computed tomography (μCT), and to compare specimens from healthy references against end-stage osteoarthritis (OA) using conventional section-based histology and qualitative μCT. Design: We retrieved human medial and lateral menisci from 10 deceased donors without knee OA (healthy references) and medial and lateral menisci from 10 patients having total knee replacement for medial compartment OA. Meniscal posterior horns were dissected and fixed in formalin. One subsection underwent hexamethyldisilazane (HMDS) treatment and μCT imaging. Pauli's histopathological scoring was performed for 3 other subsections. The differences in histopathological scores were estimated using mixed linear regression, resulting in fixed effects estimates for within-knee comparisons and adjusted for age and body mass index for between-subjects comparisons. Results: 3D visualization with μCT qualitatively revealed similar microstructural changes in the posterior horns as conventional histology. The mean histopathological score was higher for medial menisci from OA knees vs both medial reference menisci (mean difference [95% CI], 3.9 [2.6,5.3]), and lateral menisci from OA knees (3.9 [2.9,5.0]). The scores were similar between lateral menisci from OA knees and lateral reference menisci (0.8 [−0.6,2.2]), and between medial and lateral reference menisci (0.8 [−0.3,1.9]). Conclusions: HMDS-based μCT protocol allows unique 3D visualization of meniscus microstructures. Posterior horns of medial menisci from medial compartment OA knees had higher histopathological scores than both the lateral posterior horns from the same OA knees and medial reference menisci, suggesting a strong association between meniscus degradation and unicompartmental knee OA

3D morphometric analysis of calcified cartilage properties using micro-computed tomography

Abstract Objective: Our aim is to establish methods for quantifying morphometric properties of calcified cartilage (CC) from micro-computed tomography (μCT). Furthermore, we evaluated the feasibility of these methods in investigating relationships between osteoarthritis (OA), tidemark surface morphology and open subchondral channels (OSCCs). Method: Samples (n = 15) used in this study were harvested from human lateral tibial plateau (n = 8). Conventional roughness and parameters assessing local 3-dimensional (3D) surface variations were used to quantify the surface morphology of the CC. Subchondral channel properties (percentage, density, size) were also calculated. As a reference, histological sections were evaluated using Histopathological osteoarthritis grading (OARSI) and thickness of CC and subchondral bone (SCB) was quantified. Results: OARSI grade correlated with a decrease in local 3D variations of the tidemark surface (amount of different surface patterns (rs = −0.600, P = 0.018), entropy of patterns (EP) (rs = −0.648, P = 0.018), homogeneity index (HI) (rs = 0.555, P = 0.032)) and tidemark roughness (TMR) (rs = −0.579, P = 0.024). Amount of different patterns (ADP) and EP associated with channel area fraction (CAF) (rp = 0.876, P «< 0.0001; rp = 0.665, P = 0.007, respectively) and channel density (CD) (rp = 0.680, P = 0.011; rp = 0.582, P = 0.023, respectively). TMR was associated with CAF (rp = 0.926, P «< 0.0001) and average channel size (rp = 0.574, P = 0.025). CC topography differed statistically significantly in early OA vs healthy samples. Conclusion: We introduced a μ-CT image method to quantify 3D CC topography and perforations through CC. CC topography was associated with OARSI grade and OSCC properties; this suggests that the established methods can detect topographical changes in tidemark and CC perforations associated with OA