BACKGROUND: Changes in muscle mass, strength, vascular function, oxidative stress, and inflammatory biomarkers were compared in older adults after resistance training (RT) performed with low-intensity without blood flow restriction (RT-CON); low-intensity with BFR (RT-BFR); and high-intensity without BFR (RT-HI). METHODS: Thirty-two untrained individuals (72±7 y) performed a 12-week RT after being randomized into three groups: RT-CON –30% of 1 repetition maximum (RM); RT-BFR –30% of 1RM and mild BFR (50% of arterial occlusion pressure); RT-HI –70% of 1 RM. RESULTS: Improvements in handgrip strength were similar in RT-BFR (17%) and RT-HI (16%) vs. RT-CON (–0.1% ), but increases in muscle mass (6% vs. 2% and –1%) and IGF-1 (2% vs. –0.1% and –1.5%) were greater (p < 0.05) in RT-BFR vs. RT-HI and RT-CON. Changes in vascular function, morphology, inflammation, and oxidative stress were similar between groups, except for time to reach maximum red blood cell velocity which showed a greater reduction (p < 0.05) in RT-BFR (–55%) vs. RT-HI (–11%) and RT-CON (–4% ). CONCLUSION: RT with low intensity and mild BFR improved muscle strength and mass in older individuals while preserving vascular function. This modality should be considered an adjuvant strategy to improve muscle function in older individuals with poor tolerance to high loads.
Naproxen (Nap), a non‐steroidal anti‐inflammatory drug, and 5‐fluorouracil (5FU), an anticancer drug, were easily incorporated into a polyurea xerogel. Polyureas (PUr) were synthesized by one pot reaction via sol–gel chemistry. Soft segments were based on polyetheramine‐PEO and hard segments were based on a hexamethylene diisocyanate trimer (HDI). The final materials were characterized by Fourier transform infrared (FTIR) spectroscopy, small‐angle X‐ray scattering (SAXS), and differential scanning calorimetry (DSC). Polyurea can assume many forms revealing its versatility in terms of produced shapes. In good agreement with FTIR, SAXS studies showed a microphase separated structure arising from inter‐hard‐domain spacings, which remains unchanged after incorporation of the drugs. DSC analysis demonstrated that the PEO chain mobility was poorly affected after the drugs incorporation due to the solvation of the drugs through the network. The water uptake and the amount of drug released agree well, playing an important role for controlled Nap and 5FU release. This work opens positive perspectives for ocular drug delivery and wound management, due to the easy processability of the xerogel, which has high feasibility to be moldable as pharmaceutical devices for contact lenses and transdermal patches purposes containing distinct therapeutic agents.
This paper presents the influence of the presence of a modified organoclay, Cloisite® 20A (MMTA) on the structural and drug release properties of ureasil organic–inorganic hybrid. Sol–gel process was used to prepare the hybrid nanocomposites containing sodium diclofenac (DCF) at 5% wt. The effect of the amount of MMTA incorporated into the ureasil hybrid matrix was evaluated and characterized in depth by different techniques such as X-ray diffraction (XRD), small angle X-ray scattering (SAXS), differential scanning calorimetry (DSC), and swelling properties. The influence of MMTA on ureasil nanocomposites release profile was evaluated by in situ UV–vis. The diffraction patterns of the UPEO–MMTA nanocomposites showed a synergistic contribution effect that led to an intensity increase and narrowed the diffraction peaks, evidencing a crystallite PEO growth as a function of the modified nanoclay content. The interactions between polyether chains and the hydrogenated tallow of MMTA led to an easy intercalation process, as observed in UPEO–MMTA nanocomposites containing low (1% wt) or high (20% wt) nanoclay content. The waterway (channels) created in UPEO–MMTA nanocomposites contributed to a free volume increase in the swollen network compared to UPEO without MMTA. The hypothesis of the channels created after intercalation of the PEO phase in the interlayer of MMTA containing organoammonium ions corroborates with the XRD results, swelling studies by SAXS, and release assays. Furthermore, when these clay particles were dispersed in the polymeric matrix by an intercalation process, water uptake improvement was observed, with an increased amount of DCF release. The design of ureasil-MMTA nanocomposites containing modified nanoclay endows them with tunable properties; for example, swelling degree followed by amount of controlled drug release, opening the way for more versatile biomedical applications.
Here, we demonstrate a facile and scalable preparation via sol-gel chemistry of hybrid polyurea gels containing various amount of phosphorescent inorganic octahedral molybdenum cluster-based ternary salts, namely Cs2Mo6Br14. The influence...
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