Morphometric and Histopathologic Changes in Skeletal Muscle Induced for Injectable PLGA Microparticles

Abstract

SUMMARY:The administration of microencapsulated drug in a matrix acid poly(lactic-co-glycolic acid) (PLGA) by intramuscular (IM) in humans has been approved by the FDA for various applications though it is not clear what effect they have on the morphological parameters of muscle tissue. The aim of this study was to analyze the morphological changes in the skeletal muscle tissue with their use. We used 12 adult female Sprague Dawley rats (Rattus novergicus) that were injected into their right gastrocnemius muscle belly with: sterile vehicle solution (G1, n = 4), 0.5 mg PLGA microparticle (G2, n = 4) and 0.75 mg PLGA microparticle (G3, n = 4), both dissolved in a sterile vehicle solution. At 14 days post injection the number and diameter of muscle fibers, the level of inflammation and histology appearance in terms of organization of muscle fibers, cellular distribution, tissue morphology and the presence of polymer waste were determined and the results between the groups compared. The administration of the compound in a single dose did not alter the morphometric parameters (number and diameter of muscle fibers) despite generating a mild inflammation in the tissue associated with the presence of polymeric residues, suggesting that the PLGA microparticles were well tolerated by the muscle tissue at concentrations tested (0.5 and 0.75 mg).

Skeletal muscle regeneration via the chemical induction and expansion of myogenic stem cells in situ or in vitro

“…S15), but gradually degraded and became non-detectable after a month. For the muscle therapeutics, we injected 1 mg FR-np for each TA muscle repair, based on several considerations including the amount of FR-np required to achieve high myogenic induction in vitro conditions, an estimated TA muscle volume, a long-term release period (three-four weeks) and the amount of nanoparticles in the muscle tissue 27 . FR-nps-treated adult TA muscles had significantly higher sciatic compound muscle action potential (CMAP) amplitudes than the vehicle treatment (i.e., np alone as a control) at two and four weeks (Fig.…”

Celecoxib/PLGA Suprime Angiogénesis y Metástasis Pulmonar de un Cáncer Mamario Murino Experimental

“…Es así como Cx asociado a PLGA o a otro tipo de polímero son vías factibles de administración de fármacos (Vilos et al, 2012(Vilos et al, , 2014(Vilos et al, , 2015 ya que podrían disminuir la frecuencia de administración y la potencial disminución de los efectos adversos, ya que disminuye la magnitud de la cantidad de fármaco liberado en el organismo en el momento de la aplicación. Todo esto agregado a la inocuidad del PLGA al ser administrado en distintos tejidos tales como glándulas salivales o tejido muscular, lo cual lo hace un biomaterial propicio para este tipo de asociaciones (Acuña et al, 2011;Miranda et al, 2013).…”

Angiogenesis and Tumor Progression Inhibition of Cyclooxygenase-2 Selective Inhibitor Celecoxib Associated with Poly (lactic-co-glycolic acid) in Tumor Cell Line Resistant to Chemotherapy

“…The potential decrease in the total dose required for treatment, due to greater efficiency in the utilization of the administered dose and the potential reduction of adverse effects as it decreases the magnitude of the amount of drug released into the body at the time application (Saez et al, 2007), as well as the decrease in recurrence of tumors, are its main advantages . All this added to the PLGA safety when administered in different tissues such as salivary glands (Cantín et al, 2013), or muscle tissue, (Acuña et al, 2011), which makes it a favorable environment for such partnerships biomaterial.…”