ABSTRACT
Conventional bone cancer treatment often results in unwanted side effects, critical-sized bone defects, and inefficient cancer-cell targeting. Therefore, new approaches are necessary to better address bone cancer treatment and patient's recovery. One solution may reside in the combination of bone regeneration scaffolds with magnetic hyperthermia. By incorporating pristine superparamagnetic iron oxide nanoparticles (pSPIONs) into additively manufactured scaffolds we created magnetic structures for magnetic hyperthermia and bone regeneration. For this, hydroxyapatite (HA) particles were integrated in a polymeric matrix composed of chitosan (CS) and poly (vinyl alcohol) (PVA). Once optimized, pSPIONs were added to the CS/PVA/HA paste at three different concentrations (1.92, 3.77, and 5.54 wt.%), and subsequently additively manufactured to form a scaffold. Results indicate that scaffolds containing 3.77 and 5.54 wt.% of pSPIONs, attained temperature increases of 6.6 and 7.5 °C in magnetic hyperthermia testing, respectively. In vitro studies using human osteosarcoma Saos-2 cells indicated that pSPIONs incorporation significantly stimulated cell adhesion, proliferation and alkaline phosphatase (ALP) expression when compared to CS/PVA/HA scaffolds. Thus, these results support that CS/PVA/HA/pSPIONs scaffolds with pSPIONs concentrations above or equal to 3.77 wt.% have the potential to be used for magnetic hyperthermia and bone regeneration.
Subject(s)
Chitosan , Hyperthermia, Induced , Humans , Chitosan/chemistry , Durapatite/chemistry , Tissue Scaffolds/chemistry , Bone Regeneration , Magnetic Iron Oxide Nanoparticles , Magnetic Phenomena , Tissue Engineering/methodsABSTRACT
CONTEXT: Given the relatively novel technique of tissue flossing is currently lacking in the research literature despite some positive findings in preliminary studies, the modality clearly requires further research. Current evidence suggests that band flossing results in performance improvements and may also be an effective method in injury prevention. OBJECTIVE: Previous research has shown that tissue flossing may result in increased ankle range of motion, jump, and sprinting performance in recreational athletes. The present study aims to extend on this research, within an elite athlete sample. DESIGN: Counterbalanced, cross-over design with experimental and control trials, separated by 1 week. SETTING: University laboratory. PARTICIPANTS: Fourteen professional male rugby union athletes (mean [SD]: age 23.9 [2.7] y). INTERVENTION: Application of a floss band to both ankles (FLOSS) for 2 minutes or without flossing of the ankle joints (CON) on 2 separate occasions. MAIN OUTCOME MEASURES: A weight-bearing lunge test, a countermovement jump test, and a 20-m sprint test at pre and at 5 and 30 minutes post application of the floss band or control. RESULTS: There were no statistically significant interactions between treatment (FLOSS/CON) and time for any of the measured variables (P > .05). Effect size analysis revealed small benefits for FLOSS in comparison with CON for countermovement performance 5 minutes post (d = 0.28) and for 10-m (d = -0.45) and 15-m (d = -0.24) sprint time 30 minutes post. CONCLUSION: Findings from the current study suggest minimal benefits of tissue flossing when applied to the ankle joint in elite athletes for up to 30 minutes following their application.
Subject(s)
Ankle Joint/physiology , Athletic Performance/physiology , Muscle, Skeletal/blood supply , Muscle, Skeletal/physiology , Range of Motion, Articular/physiology , Therapy, Soft Tissue/instrumentation , Tourniquets , Adult , Constriction , Cross-Over Studies , Football , Humans , Male , Young AdultABSTRACT
Leucine metabolites, α-hydroxyisocaproic acid (α-HICA) and ß-hydroxy-ß-methylbutyrate (calcium, HMB-Ca and free acid, HMB-FA), have been proposed to augment resistance training-induced changes in body composition and performance. PURPOSE: We aimed to conduct a double-blind randomized controlled pragmatic trial to evaluate the effects of off-the-shelf leucine metabolite supplements of α-HICA, HMB-FA, and HMB-Ca on resistance training-induced changes in muscle thickness and performance. METHODS: Forty men were randomly assigned to receive α-HICA (n = 10, fat-free mass [FFM] = 62.0 ± 7.1 kg), HMB-FA (n = 11, FFM = 62.7 ± 10.5 kg), HMB-Ca (n = 9, FFM = 65.6 ± 10.1 kg), or placebo (PLA; n = 10, FFM = 64.2 ± 5.7 kg). The training program consisted of whole body thrice weekly resistance training for 8 wk (seven exercises per session, three to four sets per session, at 70%-80% one repetition maximum). Skeletal muscle thickness by ultrasound, performance measures, and blood measures (creatine kinase, insulin-like growth factor 1, growth hormone, cortisol, and total testosterone) were evaluated at baseline and at the end of weeks 4 and 8. RESULTS: Time-dependent changes were observed for muscle thickness (P < 0.001), one repetition maximum bench press and squat (P < 0.001), Wingate peak power (P = 0.02), countermovement jump height (P = 0.03), power (P = 0.006), creatine kinase, insulin-like growth factor-1, growth hormone, and cortisol (all P < 0.001). No significant between-group or time-group interactions were observed. CONCLUSIONS: No leucine metabolite resulted in any ergogenic effects on any outcome variable. Supplementation with leucine metabolites-α-HICA, HMB-FA, or HMB-Ca-is not a supplementation strategy that improves muscle growth and strength development in young adult men.
Subject(s)
Caproates/administration & dosage , Dietary Supplements , Muscle Strength/physiology , Muscle, Skeletal/anatomy & histology , Muscle, Skeletal/physiology , Performance-Enhancing Substances/administration & dosage , Resistance Training , Valerates/administration & dosage , Adolescent , Adult , Athletic Performance/physiology , Biomarkers/blood , Body Composition , Creatine Kinase/blood , Double-Blind Method , Human Growth Hormone/blood , Humans , Hydrocortisone/blood , Insulin-Like Growth Factor I/metabolism , Male , Middle Aged , Young AdultABSTRACT
Evidence suggests that omega-3 fatty acid supplementation could reduce muscle soreness and maintain muscle function following eccentric exercise-induced muscle damage. The aim of this applied field study was to investigate the effectiveness of consuming a protein-based supplement containing 1546â mg of omega-3 polyunsaturated fatty acid (PUFA) (551â mg eicosapentaenoic acid (EPA) and 551â mg docosahexaenoic acid (DHA)) twice daily (FO) compared to a protein-based placebo (P) on muscle soreness, countermovement jump (CMJ) performance and psychological well-being in 20 professional Rugby Union players during 5 weeks of pre-season training. Players completed a 5-point-Likert soreness scale with 5 indicating "no soreness" and a questionnaire assessing fatigue, sleep, stress and mood each morning of training, plus they performed CMJ tests once or twice per week. Data were analysed using magnitude-based inferential statistics and are presented as percent beneficial/trivial/harmful. On day 35, there was a likely (% beneficial/trivial/harmful: 94/5/1) moderate (0.75, standardized mean difference (SMD)) beneficial effect of FO vs. P on the change in lower body muscle soreness compared with day 0 (FO: -3.8 ± 21.7%; P: -19.4 ± 11.2%). There was a likely (92/7/0) moderate (SMD: 0.60) beneficial effect of FO vs. P on CMJ performance (change from baseline to day 35, FO: +4.6 ± 5.9%; P: -3.4 ± 8.6%). From day 20, a moderate beneficial effect of FO on fatigue was observed. In terms of practical relevance, the moderate beneficial effect of adding fish oil to a protein-based supplement on muscle soreness translated into the better maintenance of explosive power in elite Rugby Union players during pre-season training.
Subject(s)
Athletic Performance/physiology , Dietary Supplements , Fatty Acids, Omega-3/administration & dosage , Muscle, Skeletal/physiology , Myalgia/prevention & control , Sports Nutritional Physiological Phenomena , Adult , Affect , Athletes , Double-Blind Method , Fatigue , Fatty Acids, Omega-3/blood , Fish Oils/administration & dosage , Football , Humans , Male , Muscle Strength , Muscle, Skeletal/drug effects , Sleep , Stress, Psychological , Young AdultABSTRACT
The physical demands and combative nature of rugby lead to notable levels of muscle damage. In professional rugby, athletes only have a limited timeframe to recover following training sessions and competition. Through the implementation of recovery strategies, sport scientists, practitioners and coaches have sought to reduce the effect of fatigue and allow athletes to recover faster. Although some studies demonstrate that recovery strategies are extensively used by rugby athletes, the research remains equivocal concerning the efficacy of recovery strategies in rugby. Moreover, given the role of inflammation arising from muscle damage in the mediation of protein synthesis mechanisms, some considerations have been raised on the long-term effect of using certain recovery modalities that diminish inflammation. While some studies aimed to understand the effects of recovery modalities during the acute recovery phase (<48 h post-match), others investigated the effect of recovery modalities during a more prolonged timeframe (i.e. during a training week). Regarding the acute effectiveness of different recovery modalities, cold water immersion and contrast baths seem to provide a beneficial effect on creatine kinase clearance, neuromuscular performance and delayed onset of muscle soreness. There is support in the literature concerning the effect of compression garments on enhancing recovery from delayed onset of muscle soreness; however, conflicting findings were observed for the restoration of neuromuscular function with the use of this strategy. Using a short-duration active recovery protocol seems to yield little benefit to recovery from rugby training or competition. Given that cold modalities may potentially affect muscle size adaptations from training, their inclusion should be treated with caution and perhaps restricted to certain periods where athlete readiness is more important than increases in muscle size.