The microneedle (MN) provides a promising strategy for transdermal delivery of exosomes (EXO), in which the therapeutic effects and clinical applications are greatly reduced by the fact that EXO can only partially reach the injury site by passive diffusion. Here, we designed a detachable MN array to deliver EXO modified by a nitric oxide nanomotor (EXO/MBA) for Achilles tendinopathy (AT) healing. With the releasing of EXO/MBA, L-arginine was converted to nitric oxide by NOS or ROS as the driving force. Benefiting from the motion ability and the property of MPC tending to lower pH, EXO could accumulate at the injury site more efficiently. This work demonstrated that EXO/MBA-loaded MN notably suppressed the inflammation of AT, facilitated the proliferation of tendon cells, increased the expression of Col1a, and prevented extracellular matrix degradation, indicating its potential value in enthesiopathy healing and other related biomedical fields.

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Background/Aims: Opiates are potent analgesics but their clinical use is limited by sex-associated side effects, such as drug tolerance, opioid-induced hyperalgesia and withdrawal reaction. OPRM1, as the main receptor of opioids, plays an important role in the pharmacological process of opioids in rodents and human. We have previously investigated OPRM1, the μ opioid receptor gene, which have dozens of alternatively spliced variants probably correlating with opioid-induced effects in brain regions of four inbred mouse strains and demonstrated the strain-specific expressions of these splice variants. Also, within a strain, the regional expression patterns of some of the variants were similar while others were opposite. Thus, we are aiming to seek out the relationship between sex differences and these alternatively spliced variants. Methods: The present studies follow a SYBR green quantitative PCR (qPCR) which we had used before to examine the expression of OPRM1 splice variant mRNAs in selected brain regions of male and female C57BL/6 mice. Sex-associated differences in baseline latency, opioid-induced tolerance, analgesia and addiction were examined and determined by Tail-flick test, jumps and statistical analysis. Results: The mRNA levels of opioid receptor gene splice variants in male and female mice showed significant differences among the brain regions, implying region-specific alternative splicing of the OPRM1 gene, which was consistent with our previous study. More importantly, the complete mRNA expression profiles of the OPRM1 splice variants was also gender-specific, suggesting a sexual influence on OPRM1 alternative splicing. Conclusion: In brief, we put forward that the distinctions among baseline latency, opioid-induced tolerance, analgesia and physical dependence in male and female mice might correlate with sex associated differential expressions of OPRM1 gene.

Diabetic osteoporosis continues to surge worldwide, increasing the risk of fracture. We have previously demonstrated that haploinsufficiency of endogenous parathyroid hormone-related peptide (PTHrP) impairs fracture healing. However, whether an exogenous supply of PTHrP can repair bone damage and accelerate fracture healing remains unclear. This study aimed to assess the efficacy and safety of PTHrP in healing fractures. Standardized mid-diaphyseal femur fractures were generated in 12-week-old wild-type and leptin receptor null Lepr(-/-) mice. After administration of PTHrP for 2 weeks, callus tissue properties were analyzed by radiography, micro-computed tomography, histology, histochemistry, immunohistochemistry, and molecular biology techniques. At 2 weeks post-fracture, cartilaginous callus areas were reduced, while total callus and bony callus areas were increased in PTHrP-treated Lepr(-/-) animals and control wild-type mice, compared with vehicle-treated Lepr(-/-) mice. The following parameters were enhanced both in Lepr(-/-) mice after treatment with PTHrP and vehicle-treated wild-type animals, compared with vehicle-treated Lepr(-/-) mice: osteoblast numbers; tissue alkaline phosphatase (ALP) and Type I collagen immunopositive areas; mRNA levels of ALP, Type I collagen, osteoprotegerin, and receptor activator for nuclear factor-κ B ligand; protein levels of Runt-related transcription factor 2 and insulin-like growth factor-1; and the number and surface of osteoclasts. In conclusion, exogenous PTHrP by subcutaneous injection promotes fracture repair in Lepr(-/-) mice by increasing callus formation and accelerating cell transformation: upregulated osteoblastic gene and protein expression, increased endochondral bone formation, osteoblastic bone formation, and osteoclastic bone resorption. However, complete repair was not obtained in PTHrP-treated Lepr(-/-) mice as in control wild-type animals.