Tripolyphosphate tpp

Piperine (purity: 98%, code A13510) was purchased from Alfa Aesar (Gmbh & Co KG, Karlsrushe, Germany). Stearic acid and low-molecular-weight chitosan (100,000–300,000 Da) were obtained from Acros Organics Co., Belgium. Tween 80 was purchased from Loba Chemie Co., India. Tripolyphosphate (TPP) was purchased from Sigma-Aldrich Chemie GmbH, Japan. A dialysis tubing cellulose membrane was obtained from Sigma Co., USA, and a molecular weight cut-off of 12,000-14,000 was used. Streptozotocin (STZ) was purchased from Sigma Aldrich Chemical Co., USA. Sodium citrate, citric acid and hydrochloric acid of analytical grade were obtained from Fluka, Germany. Commercial ELISA (enzyme-linked immunosorbent assay) kits were used for the measurement of malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD), brain-derived neurotrophic factor (BDNF) and the transcription factor CREB. All the other solvents were of analytical grade.

ITR was purchased from Beta-Pharma (Shanghai, China). Poly(d,l lactic-co-glycolic acid; PLGA) (50/50, M.W. 45–70 kDa), medium molecular weight chitosan (CS), and tri polyphosphate (TPP) were purchased from Sigma-Aldrich, St. Louis, MO, USA. Β-actin (NB600-50155), Bax (NB100-609655), and Bcl2 (NB100-56098) primary antibodies were purchased from Novus Biologicals (Centennial, CO, USA). The apoptosis detection kit (556547) was purchased from BD Bioscience (NJ, USA). All other chemicals used were of analytical grade.

Chitosan (Cs) with 75–85% deacetylation and 310–375 kDa molecular weight, sodium selenite (Se), and tripolyphosphate (TPP) were obtained from Sigma-Aldrich Co (St Louis, MO, USA). Other chemicals used in this project were all analytical grade, and used without further purification. Deionized water (DIW) was used for this investigation. Cs–NPs were prepared according to a published method [25 (link)]. Briefly, a Cs solution was obtained by adding 0.5 g of Cs powder to 25 mL of 1% (by wgt) acetic acid with continuous stirring for 3 h at room temperature. Separately, 0.1 g of sodium selenite was added to 15 mL of DIW and dissolved by shaking vigorously. The Se solution was then added to the Cs solution. The ratio of Cs to TPP by weight was 2.5:1, so 0.2 g of TPP was dissolved in 10 mL of DIW and slowly added to the Cs-Se solution. The coagulum of TPP–crosslinked Cs was left to stir overnight at room temperature and subsequently, washed with excess DIW to remove unreacted starting materials. Lastly, the Cs–Se NPs were lyophilized.

Chitosan (high molecular weight (HMW), molecular weight: 310 kDa to 375 kDa, degree of deacetylation: ~75 %, Sigma Aldrich, St. Louis, MO, USA)) was used as a starting material with curcumin (~95% purity, Zhejiang metals and minerals Import and Export Corporation, Hangzhou, Zhejiang Province, China) as a model drug for nanoparticle formulation. Ethanol (≥95% Sigma Aldrich, USA), monobasic potassium phosphate (Sigma Aldrich, St. Louis, MO, USA), disodium hydrogen orthophosphate (Merck, Darmstadt, Germany), hydrochloric acid (Merck, Germany), tripolyphosphate (TPP, Sigma Aldrich, USA), acetic acid (Sigma Aldrich, St. Louis, MO, USA), sodium chloride (Sigma Aldrich, St. Louis, MO, USA) and sodium hydroxide (Sigma Aldrich, St. Louis, MO, USA) were used in nanoparticle fabrication as adjuvant chemicals. All chemicals were used without any further purification.

Low molecular weight chitosan (CS) and tripolyphosphate (TPP) was purchased from Sigma Aldrich Co. (USA_). Ciprofloxacin hydrochloride was obtained from Exir pharmaceutical Co. Tryptic soy broth culture was purchased from Merck Co. (Germany). Escherchia coli (ATCC 25922) and Staphylococcus aureus (ATCC 25923) were kindly donated by Doctor Alborzi Clinical Microbiological Research Center. All other reagents were of analytical grade and used as received.