Curcumin-Encapsulated Chitosan-Coated Nanoformulation as an Improved Otoprotective Strategy for Ototoxic Hearing Loss.

Overexpression of apoptotic factors in the inner ear is generally proven to induce ototoxicity. This has aroused research interest in various antiapoptotic drugs, the most representative of which is curcumin (CUR). In this study, two nanoformulations of CUR were developed with sustained-release behavior to improve their protective effects against ototoxic hearing loss (HL), which were the nanoparticles of CUR-loaded poly(lactic acid-glycolic acid) (CUR-PLGA NPs) and CUR-loaded chitosan-coated PLGA NPs (CUR-CS/PLGA NPs). The obtained results revealed that both CUR-NPs provided otoprotection in vitro and in vivo, and their effective doses in guinea pigs were much less than that of dexamethasone, which was clinically used to treat HL. Moreover, relative to CUR and CUR-PLGA NPs, CUR-CS/PLGA NPs exhibited the highest accumulation in HEI-OC1 cells and guinea pigs' cochlea. In pharmacodynamic experiments, the optimal administration timing was investigated, and CUR-CS/PLGA NPs showed sustained efficacy and the best hearing improvement at all tested sound frequencies. Lastly, the protective effect of CUR nanoformulations was further validated via inhibition of Caspase-3 and Bax activation, thereby reducing the concentration of reactive oxygen species and protecting mitochondrial integrity in hair cells. Collectively, CUR-CS/PLGA NPs demonstrated potent and lasting effects against ototoxic HL, making our novel formulation a promising candidate for the alleviation of sensorineural HL.

Surface engineering of semiconducting polymer nanoparticles for amplified photoacoustic imaging.

Despite the deeper tissue penetration of photoacoustic (PA) imaging, its sensitivity is generally lower than optical imaging. This fact partially restricts the applications of PA imaging and greatly stimulates the development of sensitive PA imaging agents. We herein report that the surface coating of semiconducting polymer nanoparticles (SPNs) with the silica layer can simultaneously amplify fluorescence and PA brightness while maintaining their photothermal conversion efficiency nearly unchanged. As compared with the bare SPNs, the silica-coated SPNs (SPNs-SiO2) have higher photothermal heating rate in the initial stage of laser irradiation due to the higher interfacial thermal conductance between the silica layer and water relative to that between the SP and water. Such an interfacial effect consequently results in sharp temperature increase and in turn amplified PA brightness for SPNs-SiO2. By conjugating poly(ethylene glycol) (PEG) and cyclic-RGD onto SPNs-SiO2, targeted PA imaging of tumor in living mice is demonstrated after systemic administration, showing a high signal to background ratio. Our study provides a surface engineering approach to amplify the PA signals of organic nanoparticles for molecular imaging.

[Clinical analysis of plasma cell granuloma occurred in head and neck].

OBJECTIVE: To discuss the diagnosis and treatment of plasma cell granuloma in the head and neck region. METHOD: Retrospective analysis of 3 cases of plasma cell granuloma occurred in head and neck. One case treated with endoscopic surgery and nasal and oral steroids after operation. Two cases treated with Caldwell-Luc style resection, followed by oral steroids and radiotherapy, one of the two cases combined with chemotherapy simultaneously. RESULT: The patient done with endoscopic surgery followed up for 5 years, there was no tumor recurrence in the nasal cavity and maxillary sinus openings and sinus lining. Paranasal sinus CT was examed on the patient done with partial resection and radiotherapy 2 years after operation, no residual tumor proliferation. The third patient underwent paranasal sinus CT examination 3 years after operation, and no limitation of mouth opening was found. CONCLUSION: The incidence rate of Plasma cell granuloma occured in head and neck is low. It is an inflammatory disease, but its physical signs and imaging findings are similar to malignant tumors. Because of the invasion feature, surgical resection should be the first choice, and if combined with radiotherapy and chemotherapy, the prognosis could be better.