Search

Background: Treating articular cartilage lesions is clinically challenging. However, whether the addition of autologous platelet-rich plasma (PRP) to bioimplants along with early rehabilitation exercise provides therapeutic effects and regenerates the osteochondral defect remains uninvestigated., Hypothesis: The addition of PRP to a polylactic-co-glycolic acid (PLGA) scaffold along with continuous passive motion (CPM) in osteochondral defects may offer beneficial in situ microenvironment changes to facilitate hyaline cartilage and subchondral bone tissue repair., Study Design: Controlled laboratory study., Methods: In 26 rabbits, 52 critical osteochondral defects were created in bilateral femoral trochlear grooves. The rabbits were allocated to 1 of the following 3 groups: PRP gel (PG group), PRP + PLGA scaffold (PP group), and PRP + PLGA scaffold + CPM (PPC group). At 4 and 12 weeks after surgery, the specimens were assessed by a macroscopic examination, a histological evaluation with immunohistochemical staining, and micro-computed tomography., Results: The PPC group exhibited the most favorable therapeutic outcomes in terms of hyaline cartilage regeneration. At week 4, the PPC group exhibited significantly higher levels of glycosaminoglycan (GAG) and collagen (COL) II and modest increases in COL I, matrix metalloproteinase-3 (MMP-3), and inflammatory cells with tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6). At week 12, the PPC group had significantly higher tissue repair scores, corresponding to a sound articular cartilage surface and chondrocyte and collagen arrangement. This group demonstrated restored hyaline cartilage and mineralized bone volume per tissue volume, which had an integrating structure in the repair site. However, the PG and PP groups exhibited mainly fibrous tissue and fibrocartilage, corresponding to higher expressions of COL I, TNF-α, IL-6, and MMP-3., Conclusion: PRP with a PLGA graft along with early CPM exercise is promising for the repair of osteochondral defects in rabbit knee joints., Clinical Relevance: This study demonstrates the efficacy of a triad therapy involving the addition of PRP to bioimplants along with early CPM intervention for hyaline cartilage and subchondral regeneration. However, PRP alone (with or without PLGA implants) is limited to osteochondral defect repair without significant regeneration.

Background: Effective postoperative pain control is essential for the recovery of surgical patients. However, long-term analgesia can seldom be achieved with the existing medications. The injectable implants prepared by biodegradable polyesters can be conveniently used during the surgery and slowly release analgesics near the operative incision for a long period., Method: In this study, we prepared lidocaine hydrochloride (Lido-HCl)-loaded injectable poly(lacticco- glycolic acid) (PLGA) implants for prolonged analgesia. The optimized formulation of this injectable implant sustained drug release for up to 5 days, with a cumulative release of 85.8%±1.9% in the in vitro release experiment., Results: The in vivo release of the implants in rats showed good consistency with the in vitro release. The pharmacokinetics of Lido-HCl implants in the thigh muscle of rats was evaluated, and the AUC0-120 h of the Lido-HCl implant was 11.4 times that of Lido-HCl solution, indicating a good sustained release function of the implant. The pharmacodynamics of Lido-HCl implants was measured by the hot plate test. The Lido-HCl solution blocked the sciatic nerve of rats for less than 4 h, while the Lido-HCl implant efficiently blocked the nerve for approximately 120 h., Conclusion: These results demonstrated that the PLGA-based injectable implant is a suitable carrier for postoperative pain control., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

Persistent luminescence nanoparticles (PLNPs) have been used for bioimaging without autofluorescence background interference, but the poor afterglow performance impedes their further applications in cancer therapy. To overcome the Achilles' heel of PLNPs, herein we report the construction of injectable persistent luminescence implants (denoted as PL implants) as a built-in excitation source for efficient repeatable photodynamic therapy (PDT). The injectable ZGC (ZnGa 1.996 O 4 :Cr 0.004 ) PL implants were prepared by dissolving ZGC PLNPs in poly(lactic-co-glycolic acid)/N-methylpyrrolidone oleosol, which demonstrated much stronger persistent luminescence (PersL) intensity and longer PersL lifetime than that of ZGC PLNPs both in vitro and in vivo. More importantly, the intratumorally fixed ZGC PL implants can serve as a built-in excitation source for repeatable light emitting diode (LED) and PersL-excited PDT upon and after periodic LED irradiation, which leads to the overall improvement of therapeutic effectiveness for efficient tumor growth suppression. This work represents efficient repeatable PDT based on the injectable yet periodically rechargeable ZGC PL implants.

Background/aims: Every year, around the world, between 250000 and 500000 people suffer from spinal cord injury (SCI). This study investigated the potential for poly (lactic-co-glycolic acid) (PLGA) complex inoculated with olfactory ensheathing cells (OECs) to treat spinal cord injury in a rat model., Methods: OECs were identified by immunofluorescence based on the nerve growth factor receptor (NGFR) p75. The Basso, Beattie, and Bresnahan (BBB) score, together with an inclined plane (IP) test were used to detect functional recovery. Nissl staining along with the luxol fast blue (LFB) staining were independently employed to illustrate morphological alterations. More so, immunofluorescence labeling of the glial fibrillary acidic protein (GFAP) and the microtubule-associated protein-2 (MAP-2), representing astrocytes and neurons respectively, were investigated at time points of weeks 2 and 8 post-operation., Results: The findings showed enhanced locomotor recovery, axon myelination and better protected neurons post SCI when compared with either PLGA or untreated groups (P < 0.05)., Conclusion: PLGA complexes inoculated with OECs improve locomotor functional recovery in transected spinal cord injured rat models, which is most likely due to the fact it is conducive to a relatively benevolent microenvironment, has nerve protective effects, as well as the ability to enhance remyelination, via a promotion of cell differentiation and inhibition of astrocyte formation., (© 2017 The Author(s)Published by S. Karger AG, Basel.)