Enhanced Osteogenic Activity and Bone Repair Ability of PLGA/MBG Scaffolds Doped with ZIF-8 Nanoparticles Loaded with BMP-2.

Background: Tissue engineering scaffolds are porous and can be loaded with growth factors to promote osteogenesis and bone repair, which can solve the problem of clinical bone defects. The direct loading of growth factors on scaffolds is hindered by the disadvantages of low loading capacities, and uncontrollable burst release. Zeolitic imidazolate framework-8 (ZIF-8) has osteoinductive activity and drug-loading potential and can be loaded with growth factors to achieve sustained release. In this study, we aimed to establish a sustained release system of composite scaffolds loaded with growth factors to achieve the goal of slow controlled release and effective bone repair. Methods: ZIF­8 nanoparticles loaded with bone morphogenetic protein-2 (BMP-2) were incorporated into poly-(lactide-co-glycolide)/mesoporous bioactive glass (PLGA/MBG) porous scaffolds by a 3D-printing method. The surface morphology, chemical properties and BMP-2 release of the prepared scaffold were investigated. The osteoblast adhesion, proliferation, spreading, and osteogenic differentiation in vitro and the bone repair ability in vivo of the PLGA/MBG/ZIF-8/BMP-2 (PMZB) scaffold were evaluated, and compared with those of PLGA/MBG (PM) and PLGA/MBG/ZIF-8 (PMZ) scaffolds. Results: The results showed that the PMZB scaffold exhibited a slow and continuous BMP-2 release pattern, enhanced osteoblast adhesion, proliferation, spreading and osteogenic differentiation in vitro, and promoted new bone formation and bone repair in vivo. Conclusion: The PLGA/MBG/ZIF-8/BMP-2 porous scaffold could continuously and slowly release BMP-2, enhance osteogenic activity, and promote new bone formation and bone repair at bone defects. The PMZB scaffold can be used as a bone graft material to repair bone defect at non-weight-bearing sites.

Additively manufactured polyether ether ketone (PEEK) skull implant as an alternative to titanium mesh in cranioplasty.

173Cranioplasty is used for skull defects, involving lifting the scalp and restoring the contour of the skull with the original skull piece, titanium mesh, or solid biomaterial. Additive manufacturing (AM) technology, known as three-dimensional (3D) printing, is now utilized by medical professionals to develop customized replicas of tissues, organs and bones, offering a valid option with perfect anatomic fitting in the individual and skeletal reconstruction. Here, we report a case that underwent titanium mesh cranioplasty 15 years ago. The poor appearance of the titanium mesh weakened the left eyebrow arch and resulted in the formation of a sinus tract. Cranioplasty was performed using an additively manufactured polyether ether ketone (PEEK) skull implant. PEEK skull implants have been successfully implanted without any complications. To our knowledge, this is the first reported case of direct use of fused filament fabrication (FFF)-fabricated PEEK implant for cranial repair. The FFF-printed PEEK customized skull implant could possess simultaneously with adjustable material thickness and more complex structure, tunable mechanical properties, and low processing costs compared with traditional manufacturing processes. While meeting clinical needs, this production method is an appropriate alternative for promoting the use of PEEK materials in cranioplasty.

Additive manufactured polyether-ether-ketone implants for orthopaedic applications: a narrative review.

Polyether-ether-ketone (PEEK) is believed to be the next-generation biomedical material for orthopaedic implants that may replace metal materials because of its good biocompatibility, appropriate mechanical properties and radiolucency. Currently, some PEEK implants have been used successfully for many years. However, there is no customised PEEK orthopaedic implant made by additive manufacturing licensed for the market, although clinical trials have been increasingly reported. In this review article, design criteria, including geometric matching, functional restoration, strength safety, early fixation, long-term stability and manufacturing capability, are summarised, focusing on the clinical requirements. An integrated framework of design and manufacturing processes to create customised PEEK implants is presented, and several typical clinical applications such as cranioplasty patches, rib prostheses, mandibular prostheses, scapula prostheses and femoral prostheses are described. The main technical challenge faced by PEEK orthopaedic implants lies in the poor bonding with bone and soft tissue due to its biological inertness, which may be solved by adding bioactive fillers and manufacturing porous architecture. The lack of technical standards is also one of the major factors preventing additive-manufactured customised PEEK orthopaedic implants from clinical translation, and it is good to see that the abundance of standards in the field of additive-manufactured medical devices is helping them enter the clinical market.

Evaluation of the Effect of Sprout Soybeans on the Iron Status of Anemic Adolescent Girls in Rural China.

Soybeans are a major source of nonheme iron in Chinese diet. Germination is considered to be effective in improving iron bioavailability in soybeans. The study is to evaluate the effect of sprout soybean supplementation on the iron status of anemic adolescent girls in rural area of China and to compare it with the effect of soybeans. Two hundred and eighty eight adolescent girls were assigned to receive one of three dietary supplements (100 mL) a day for 6 m: 1) rice milk as the control (C); 2) sprout soybean milk (SS); 3) soybean milk (S). In addition to anthropometric measurements, iron status was measured at baseline and at the end of the study. After six months, the concentration of hemoglobin and plasma ferritin of participants in sprout soybean group were 138.6 ± 6.3 g/L and 43.3 ± 12.6 µg/L, significantly higher than those of the control. Significant decreases in the rate of anemia, iron deficiency and free erythrocyte protoporphyrin (FEP) concentration were found both in sprout soybean and soybean group. An obvious decrease in plasma transferritin receptor was found in the sprout soybean group comparing with the control, but not in the soybean group. Small but not significant differences were found in all iron indicators between the sprout soybean and soybean group. Sprout soybeans and soybeans could improve the iron status of anemic adolescent girls. Although sprout soybeans exhibited some priority to soybeans, no absolutely significant difference was found between them.

Effect of lithocholic acid on biologically active α,ß-unsaturated aldehydes induced by H2O2 in glioma mitochondria for use in glioma treatment.

Lithocholic acid (LCA) is known to kill glioma cells while sparing normal neuronal cells. However, the anti-glioma mechanism of LCA is unclear at present. Although malondialdehyde (MDA) is not specific to detect tumors, biologically active α,ß-unsaturated aldehydes can be used to detect the outcome of gliomas, especially the mitochondria, as a research tool. The purpose of this research was to determine the optimum conditions for a lipid peroxidation model, according to changes in the aldehydes formed from the reaction between 2-thiobarbituric acid and biologically active α,ß-unsaturated aldehydes. Experimental methods and procedures were successfully established for a model of lipid peroxidation induced by H2O2 in glioma mitochondria for glioma treatment and optimum conditions for LCA treatment were determined. The optimal conditions for the model were a glioma mitochondrial concentration of 1.5 mg/ml, H2O2 concentration of 0.3 mg/ml, duration of action of 30 min, and addition of 4.0 ml of 46 mM thiobarbituric acid. The effect of LCA, as determined by changes in the UV peaks at 450, 495, and 532 nm, was optimal at a concentration of 100 µM, a duration of action of 15 min, and in an acidic microenvironment. The study concluded that a suitable concentration of LCA has anti-glioma effects as determined by the effect on changes in the UV peaks at 450, 495 and 532 nm and the mitochondrial model developed should be conducive to further in-depth research.

Association of IL33/ST2 signal pathway gene polymorphisms with myocardial infarction in a Chinese Han population.

This study investigated the relationship between IL-33/ST2 signal pathway gene polymorphisms and myocardial infarction (MI) in Han Chinese. A case-control association analysis was performed on a total of 490 MI patients (MI group) and 929 normal subjects (NC group). Sequenom Mass Array and Taqman genotyping technique were used to analyze the tag single nucleotide polymorphisms (SNPs) in the genes encoding IL-33, ST2, and IL-1RaP (rs11792633, rs1041973 and rs4624606). The results showed that the frequencies of rs4624606 genotypes AA, TT, AT were 0.031, 0.647, 0.322 in MI group and 0.026, 0.712, 0.263 in NC group, and the allele frequencies of A and T were 0.192, 0.808 in MI group and 0.157, 0.843 in NC group. There were significant differences in rs4624606 genotypes and allele frequencies between MI group and NC group (P<0.05). For rs11792633, the allele frequencies of C and T were 0.45, 0.55 in MI group and 0.454, 0.546 in NC group with no significant differences found between the two groups. Compared with genotype CC+TC, rs11792633 genotype TT had an increased risk of hypertension (P<0.05). However, there were no significant differences in the frequencies of rs11792633 genotypes between the two groups. No significant differences were noted in the frequencies of rs1041973 genotype and allele between the two groups. Logistic regression analysis showed that rs4624606 genotypes AT and AA+AT were both significantly associated with MI (AT: OR=1.325, P=0.029, 95% CI=1.03-1.705; AA+AT: OR=1.316, P=0.028, 95% CI=1.03-1.681) after factors such as age, gender, smoking, drinking, body mass index (BMI), triglyceride (TG) and cholesterol were adjusted. Those carrying rs4624606 genotype AT or AA+AT had an increased risk of MI. No associations were found between the polymorphisms of the other two loci with MI. It was concluded that, in the IL33/ST2 signal pathway, the A allele of rs4624606 polymorphism of IL-1RaP gene is a potential independent risk factor for MI, and the genotypes AA+AT and AT are associated with the incidence of MI.