Chitosan oligomers as drug carriers for renal delivery of zidovudine

► Novel zidovudine (AZT)-chitosan oligomers (COS) conjugates were prepared. ► COS were found to significantly accumulated in kidney after i.v. injection. ► COS carriers prolonged the blood retention time of AZT after i.v. injection. ► The prodrugs of AZT-COS conjugates were renal targeting after i.v. injection. ► The polymerization degree of COS might influence its renal targeting efficiency.