Hydroxyapatite/Polyurethane Scaffolds for Bone Tissue Engineering.

Polyurethane (PU) and PU ceramic scaffolds are the principal materials investigated for developing synthetic bone materials due to their excellent biocompatibility and biodegradability. PU has been combined with calcium phosphate (such as hydroxyapatite [HA] and tricalcium phosphate) to prepare scaffolds with enhanced mechanical properties and biocompatibility. This article reviews the latest progress in the design, synthesis, modification, and biological attributes of HA/PU scaffolds for bone tissue engineering. Diverse HA/PU scaffolds have been proposed and discussed in terms of their osteogenic, antimicrobial, biocompatibility, and bioactivities. The application progress of HA/PU scaffolds in bone tissue engineering is predominantly introduced, including bone repair, bone defect filling, drug delivery, and long-term implants.

Genetically predicted 486 blood metabolites concerning risk of systemic lupus erythematosus: a Mendelian randomization study.

Metabolic abnormalities constitute a significant characteristic of systemic lupus erythematosus (SLE). We utilised a two-sample Mendelian randomisation (MR) study to evaluate the potential causal association between 486 blood metabolites and SLE. Exposure data at the metabolite level were extracted from 7824 European Genome-wide association studies (GWAS). Preliminary analysis utilised SLE GWAS data from FinnGen. The primary method for causal analysis relied on random inverse variance weighting (IVW). To ensure robustness, sensitivity analyses included the Cochran Q test, MR-Egger intercept test, MR-PRESSO, and leave-one-out analysis. Steiger testing and linkage disequilibrium score regression were employed to validate the identified metabolites. This study identified 12 metabolites, comprising six known chemical structures: 1,5-anhydroglucitol(1,5-AG) [odds ratio (OR) = 0.100, 95% confidence interval (CI): 0.015-0.773, P = 0.027), gamma-glutamylthreonine (OR = 0.077, 95% CI: 0.010-0.574, P = 0.012), 5-dodecenoate(12:1n7) (OR = 0.205, 95% CI: 0.061-0.685, P = 0.010), linoleoylglycerophosphoethanolamine * (OR = 0.159, 95% CI: 0.027-0.933, P = 0.044), erythrose (OR = 88.331,95% CI:1.098-63.214, P = 0.040) and 1-, adrenate (22:4n6) (OR = 9.876, 95% CI: 1.753-55.639, P = 0.001)]. Additionally, we found associations between SLE and six unknown chemical structures: X-06351 (OR = 0.071, 95% CI: 0.006-0.817, P = 0.034), X-10810 (OR = 4.268 95% CI: 1.260-14.459, P = 0.020), X-11412 (OR = 5.418 95% CI: 1.068-27.487, P = 0.041), X-11905 (OR = 0.551, 95%CI: 0.304-0.997, P = 0.049), X-12038 (OR = 0.178 95%CI: 0.032-0.988, P = 0.045), X-12217 (OR = 0.174 95%CI: 0.044-0.680, P = 0.014). This study offers evidence supporting a causal relationship between SLE and 12 circulating metabolites, six of which have known chemical structures and six that remain unidentified. These findings introduce a new perspective for further exploration of SLE mechanisms.

Porous PVA/SA/HA hydrogels fabricated by dual-crosslinking method for bone tissue engineering.

In the present work, a new kind of porous polyvinyl alcohol/sodium alginate/hydroxyapatite (PVA/SA/HA) composite hydrogels with tunable structure and mechanical properties have been fabricated by dual-crosslinking method. The morphologies, moisture content, porosity and mechanical properties of the composite hydrogels have been investigated in detail. The PVA/SA/HA hydrogels present uniform, interpenetrating porous structure. The FTIR and XRD results indicate that PVA, SA and HA could be uniformly compounded. The mechanical properties, moisture content and porosity of the samples could be controlled by changing the mass ratio of PVA/SA/HA. The optimized compression modulus (41.74 ± 7.86 kPa), moisture content (86.99 ± 0.72%) and porosity (79.98 ± 1.61%) of the composite hydrogels could be achieved via fixing the weight ratio of PVA/SA/HA at 42:18:40. In vitro biodegradation and mineralization of the composite hydrogels show that the hydrogels could gradually be degraded in PBS solution and sheet-like HA nanocrystals are easily formed on the surface. Moreover, cell culture results indicate that the PVA/SA/HA hydrogels have no negative effects on MC3T3-E1 cell growth and proliferation. Alkaline phosphatase (ALP) activity expressions demonstrate that the nano-HA crystals incorporated composite hydrogels obviously improve the ALP activity of the cells. It confirms that the prepared PVA/SA/HA hydrogels could be a promising candidate for bone repair and bone tissue engineering.