title: Direct Cytoplasmic Delivery and Nuclear Targeting Delivery of HPMA-MT Conjugates in a Microtubules Dependent Fashion.
abstract: As the hearts of tumor cells, the nucleus is the ultimate target of many chemotherapeutic agents and genes. However, nuclear drug delivery is always hampered by multiple intracellular obstacles, such as low efficiency of lysosome escape and insufficient nuclear trafficking. Herein, an N-(2-hydroxypropyl) methacrylamide (HPMA) polymer-based drug delivery system was designed, which could achieve direct cytoplasmic delivery by a nonendocytic pathway and transport into the nucleus in a microtubules dependent fashion. A special targeting peptide (MT), derived from an endogenic parathyroid hormone-related protein, was conjugated to the polymer backbone, which could accumulate into the nucleus a by microtubule-mediated pathway. The in vitro studies found that low temperature and NaN3 could not influence the cell internalization of the conjugates. Besides, no obvious overlay of the conjugates with lysosome demonstrated that the polymer conjugates could enter the tumor cell cytoplasm by a nonendocytic pathway, thus avoiding the drug degradation in the lysosome. Furthermore, after suppression of the microtubule dynamics with microtubule stabilizing docetaxel (DTX) and destabilizing nocodazole (Noc), the nuclear accumulation of polymeric conjugates was significantly inhibited. Living cells fluorescence recovery after photobleaching study found that the nuclear import rate of conjugates was 2-fold faster compared with the DTX and Noc treated groups. These results demonstrated that the conjugates transported into the nucleus in a microtubules dependent way. Therefore, in addition to direct cytoplasmic delivery, our peptide conjugated polymeric platform could simultaneously mediate nuclear drug accumulation, which may open a new path for further intracellular genes/peptides delivery.
authors.affiliation: Key Laboratory of Drug Targeting and Drug Delivery System (Ministery of Education), West China School of Pharmacy, Sichuan University , NO. 17, Block 3, South Renmin Road, Chengdu 610041, P.R. China.
authors.forename: Jiaju
authors.initials: J
authors.lastname: Zhong
authors.affiliation: Key Laboratory of Drug Targeting and Drug Delivery System (Ministery of Education), West China School of Pharmacy, Sichuan University , NO. 17, Block 3, South Renmin Road, Chengdu 610041, P.R. China.
authors.forename: Xi
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital, Sichuan University , Chengdu 610041, China.
authors.forename: Kui
authors.initials: K
authors.lastname: Luo
authors.affiliation: Key Laboratory of Drug Targeting and Drug Delivery System (Ministery of Education), West China School of Pharmacy, Sichuan University , NO. 17, Block 3, South Renmin Road, Chengdu 610041, P.R. China.
authors.forename: Lian
authors.initials: L
authors.lastname: Li
authors.affiliation: Key Laboratory of Drug Targeting and Drug Delivery System (Ministery of Education), West China School of Pharmacy, Sichuan University , NO. 17, Block 3, South Renmin Road, Chengdu 610041, P.R. China.
authors.forename: Manlin
authors.initials: M
authors.lastname: Tang
authors.affiliation: Key Laboratory of Drug Targeting and Drug Delivery System (Ministery of Education), West China School of Pharmacy, Sichuan University , NO. 17, Block 3, South Renmin Road, Chengdu 610041, P.R. China.
authors.forename: Yanxi
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Key Laboratory of Drug Targeting and Drug Delivery System (Ministery of Education), West China School of Pharmacy, Sichuan University , NO. 17, Block 3, South Renmin Road, Chengdu 610041, P.R. China.
authors.forename: Zhou
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Drug Targeting and Drug Delivery System (Ministery of Education), West China School of Pharmacy, Sichuan University , NO. 17, Block 3, South Renmin Road, Chengdu 610041, P.R. China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Huang
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000502:physiology; D017209:Apoptosis / Q000502:physiology; D003593:Cytoplasm / Q000378:metabolism*; D036681:Fluorescence Recovery After Photobleaching; D006367:HeLa Cells; D006801:Humans; D008689:Methacrylates / Q000737:chemistry*; D008870:Microtubules / Q000737:chemistry / Q000378:metabolism*; D011108:Polymers / Q000737:chemistry*
chemical_list: D008689:Methacrylates; D011108:Polymers; C032802:hydroxypropyl methacrylate
keywords: HPMA copolymer; cancer therapy; cytoplasmic delivery; microtubules; nuclear drug delivery