Evolution of silicate bioglass particles as porous microspheres with a view towards orthobiologics

Production of Nano Hydroxyapatite and Mg-Whitlockite from Biowaste-Derived products via Continuous Flow Hydrothermal Synthesis: A Step towards Circular Economy

Biowastes from agriculture, sewage, household wastes, and industries comprise promising resources to produce biomaterials while reducing adverse environmental effects. This study focused on utilising waste-derived materials (i.e., eggshells as a calcium source, struvite as a phosphate source, and CH₃COOH as dissolution media) to produce value-added products (i.e., calcium phosphates (CaPs) derived from biomaterials) using a continuous flow hydrothermal synthesis route. The prepared materials were characterised via XRD, FEG-SEM, EDX, FTIR, and TEM analysis. Magnesium whitlockite (Mg-WH) and hydroxyapatite (HA) were produced by single-phase or biphasic CaPs by reacting struvite with either calcium nitrate tetrahydrate or an eggshell solution at 200 °C and 350 °C. Rhombohedral-shaped Mg-WH (23-720 nm) along with tube (50-290 nm diameter, 20-71 nm thickness) and/or ellipsoidal morphologies of HA (273-522 nm width) were observed at 350 °C using HNO₃ or CH₃COOH to prepare the eggshell and struvite solutions, and NH₄OH was used as the pH buffer. The Ca/P (atomic%) ratios obtained ranged between 1.3 and 1.7, indicating the formation of Mg-WH and HA. This study showed that eggshells and struvite usage, along with CH₃COOH, are promising resources as potential sustainable precursors and dissolution media, respectively, to produce CaPs with varying morphologies.

Can phosphatidylcholine increase the efficacy of bioactive glass graft when used as a carrier? an experimental study

Aim: Bioactive glass (Bioglass) is a substance causing strong mechanical bondings at the interface of soft tissue-biomaterial-bone through a series of biochemical and biophysical reactions, commonly used to restore developing bone defects due to surgery. On the other hand, phosphatidylcholine is a lipid substance increasing antibiotics’ efficiency as a carrier. Since we met no study using the combination of Bioglass and phosphatidylcholine for bone defects, we aimed to investigate whether the bioglass-phosphatidylcholine combination would be more effective. Material and Method: Thirty Sprague-Dawley 3-6-months-old female rats with a mean weight of 400 gr were divided into five subgroups (six in each group). A 5-mm critical defect was created in the middle of the condyle throughout the burr’s diameter bilaterally. The phosphatidylcholine-bioglass graft was placed at one side, and Bioglass contralaterally to fill the defect. The rats were sacrificed at 24 hours, 72 hours, first, third, and sixth weeks postoperatively. The right and left rat femurs were removed and examined histopathologically. Results: There was no statistically significant difference between the groups regarding filling volume, newly formed and necrotic bone, fibrous tissue, residual graft material, integration, foreign body reaction, and defect organization, indicating that Bioglass served efficiently for filling the defect. In addition, phosphatidylcholine neither augmented nor impaired the healing process. Conclusion: These results indicated that Bioglass served efficiently for filling the defect, and the presence of phosphatidylcholine neither augmented nor impaired the healing process. However, further experimental studies are required until its clinical application is implemented.

Integration of Bioglass Into PHBV-Constructed Tissue-Engineered Cartilages to Improve Chondrogenic Properties of Cartilage Progenitor Cells

Background: The Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) scaffold has proven to be a promising three-dimensional (3D) biodegradable and bioactive scaffold for the growth and proliferation of cartilage progenitor cells (CPCs). The addition of Bioglass into PHBV was reported to increase the bioactivity and mechanical properties of the bioactive materials.

Methods: In the current study, the influence of the addition of Bioglass into PHBV 3D porous scaffolds on the characteristics of CPC-based tissue-engineered cartilages in vivo were compared. CPCs were seeded into 3D macroporous PHBV scaffolds and PHBV/10% Bioglass scaffolds. The CPC–scaffold constructs underwent 6 weeks in vitro chondrogenic induction culture and were then transplanted in vivo for another 6 weeks to evaluate the difference between the CPC–PHBV construct and CPC–PHBV/10% Bioglass construct in vivo.

Results: Compared with the pure PHBV scaffold, the PHBV/10% Bioglass scaffold has better hydrophilicity and a higher percentage of adhered cells. The CPC–PHBV/10%Bioglass construct produced much more cartilage-like tissues with higher cartilage-relative gene expression and cartilage matrix protein production and better biomechanical performance than the CPC–PHBV construct.

Conclusion: The addition of Bioglass into 3D PHBV macroporous scaffolds improves the characteristics of CPC-based tissue-engineered cartilages in vivo.