In this study, we demonstrated that bovine serum albumin (BSA) can form nanospheres by desolvation method and can be used for local drug delivery. BSA is a natural protein able to form complexes in various shapes. This protein is biocompatible, biodegradable, nontoxic, and nonimmunogenic. Due to

these features, albumin particles are a good system for drug and antigen delivery [11–14]. To the best of our knowledge, there have been no reports of local delivery of drug-loaded albumin particles into the inner ear. Here, we illustrate a method for creating sphere-shaped BSA nanoparticles (BSA-NPs) with biocompatibility in high yield. A model drug, rhodamine B (RhB), was loaded onto the BSA-NPs for drug loading capacity, release, and in vivo studies. In vivo biodistribution suggested that the RhB released as QNZ order well as the RhB-loaded BSA-NPs (RhB-BSA-NPs) tended to accumulate and penetrate through the RWM of guinea pigs. Therefore, the BSA-NPs would be prospectively considered as controlled release carriers for local drug delivery in the treatment of inner ear disorders. Methods Materials,

mice, and cell culture BSA and RhB were purchased from Sigma-Aldrich (St. Louis, MO, USA). Cell counting kit-8 (CCK-8) was purchased Compound C from Dojindo Molecular Technology Inc. (Shanghai, People’s Republic of China). Ultrapure water used in all experiments was produced by Milli-Q synthesis system (Millipore Corp., Billerica, MA, USA). L929 mouse fibroblast cells (obtained from the Cancer Institute of the Chinese Academy of Medical Sciences, People’s Republic of China) were cultured in Dulbecco’s modified Eagle’s medium (DMEM) (HyClone, Thermo Scientific Inc., Waltham, MA, USA) containing 10% fetal PRKACG bovine serum (FBS) at 37°C with 5% CO2. Guinea pigs weighing 250 ~ 300 g were purchased from the Tianjin Experimental Animal

Center, People’s Republic of China, and had free access to food and water. Animal study protocols were approved and performed in accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals. Preparation of BSA-NPs and RhB-BSA-NPs BSA-NPs were prepared by the desolvation method. Briefly described, 100 mg of BSA was dissolved in 1 ml of sodium chloride solution (10 mM). Then, 8.0 ml of ethanol was added dropwise into the BSA solution under LY2606368 clinical trial magnetic stirring (400 rpm) at room temperature. Subsequently, the as-prepared BSA-NPs were cross-linked with 0.2% glutaraldehyde (GA) for 24 h or denatured at 70°C for 30 min. BSA-NPs (50 mg) were incubated with certain amounts (5, 10, 15, 17.5, and 20 mg) of RhB for 2 h in the preparation of RhB-BSA-NPs. The particles were centrifuged and washed with ultrapure water.