Stereolithographic fabrication of three-dimensional permeable scaffolds from CaP/PEGDA hydrogel biocomposites for use as bone grafts.

Polyethylene glycol diacrylate-based hydrogels filled with calcium phosphates (CaP, Ca/P < 1.5) were stereolithographically fabricated as three-dimensional permeable biocomposites for bone tissue regeneration, probed by several instrumental techniques (including scanning electron microscopy, infrared and UV-vis spectroscopy), and subjected to rheological/mechanical property analysis. As the CaP content increased from 0 to 10 wt%, Young's modulus and mechanical strength increased from 4 to 11 kPa and from 34 to 167 kPa, respectively. Moreover, the enhanced elastic properties and tuneable swelling behaviour of the fabricated composites made them well suited for bone defect filling.

Effect of amino acids on IGF1 gene expression in human myotubes and skeletal muscle.

OBJECTIVE: Insulin-like growth factor I (IGF1) is an important regulator of collagen and extracellular matrix protein expression. We aimed to evaluate the effect of amino acids (AAs) on expression of IGF1 and IGF1-dependent genes in human myotubes and skeletal muscle and supposed that AAs administration increases IGF1 levels in blood and expression of IGF1 and IGF1-dependent genes in trained skeletal muscle, thereby reducing training-induced muscle damage. DESIGN: Human myotubes were incubated with Arg and Leu for 24 h. Then, the effects of long-term branched chain AAs administration (10 weeks, 0.1 g/kg body mass/day) to volunteers (six subjects per AAs and placebo groups) performing large training volumes regularly (cross country skiers, training twice a day) were examined. RESULTS: Incubating the myotubes with AAs increases expression of IGF1 mRNA isoforms and IGF1 secretion by 2-3 times. In athletes, long-term AAs administration increased basal blood levels of IGF1 (~50%) and expression of IGF1Ea mRNA slightly in skeletal muscle. There is no marked increase in expression of COL1A1, COL3A1, COL5A1, and LOX genes in skeletal muscle after AAs administration. However, expression of these genes in the combined group (placebo + AAs; n = 12) significantly correlated with the expression of IGF1Ea mRNA in muscle and did not correlate with IGF1 levels in the blood. CONCLUSIONS: AAs administration increases IGF1 expression in vitro and in vivo. To obtain more pronounced changes in expression of IGF1 and IGF1-dependent genes in skeletal muscle, it may be necessary to increase the dose and/or duration of AAs administration.

Clinical experience with combined reconstruction of the anterior cruciate and anterolateral ligaments of the knee in sportsmen.

BACKGROUND: Rupture of the anterior cruciate ligament (ACL) is one of the most common sports injuries of the knee joint. Today, we have a large number of approaches to arthroscopic reconstruction of the anterior cruciate ligament that lead to successful outcomes and allow the patients to return to a significant level of activity post-operatively. Nevertheless, the return to competitions rate stays relatively low. The functional state is thought to be dependent on rotational and anteroposterior stability of the knee. These data encourage search for methods of additional stabilization of the knee joint, one of them being extra-articular tenodesis, or reconstruction of anterolateral ligament of the knee. THE AIM OF THE STUDY: To evaluate medium-term results of combined simultaneous arthroscopic reconstruction of anterior cruciate ligament and anterolateral ligament of the knee joint in sportsmen and to access the probability of return to competitions. MATERIALS AND METHODS: The surgeries were performed in 2014-2015 in 50 patients who fulfilled the entry criteria: 20 patients (including 10 professional sportsmen) underwent arthroscopic ACL reconstruction together with reconstruction of anterolateral ligament-group 1 (main group), and 30 patients (including 10 professional sportsmen) underwent arthroscopic ACL reconstruction-group 2 (control group). RESULTS: Group 1: All patients of group 1 were able to return to the pre-operative sports level in two years after the surgery. The mean Tegner Lysholm score was 72.6 ± 6.45 (hereinafter, SE-standard error) before the surgery and 97.4 ± 1.18 after the surgery. The mean IKDC score was 63.1 ± 4.8% before the surgery and 96.3 ± 1.8% after the surgery. Group 2: 20 of 30 patients (66.7%) returned to the pre-operative level of activity and returned to competitions (if they were professional sportsmen) in a year after the surgery. Five of ten patients (50%) (professional sportsmen) returned to competitions. Fifteen of 20 patients (75%) (amateur sportsmen) also returned to competitions. The mean pre-operative Tegner Lysholm score was 69.6 ± 3.5, and the mean post-operative score was 92.1 ± 3.9. The mean pre-operative IKDC score was 73.4 ± 3.2%, and the mean post-operative score was 90.3 ± 3.7%. CONCLUSION: The results of the study show that more patients with higher functional demands and more professional sportsmen returned to sports. Despite the results of our and other foreign studies, a need remains for studies that will compare outcomes of ALL reconstruction with the same surgical technique in homogenous groups of patients.