Multivalent benzoboroxole functionalized polymers as gp120 glycan targeted microbicide entry inhibitors.
Microbicides are women-controlled prophylactics for sexually transmitted infections. The most important class of microbicides target HIV-1 and contain antiviral agents formulated for topical vaginal delivery. Identification of new viral entry inhibitors that target the HIV-1 envelope is important because they can inactivate HIV-1 in the vaginal lumen before virions can come in contact with CD4+ cells in the vaginal mucosa. Carbohydrate binding agents (CBAs) demonstrate the ability to act as entry inhibitors due to their ability to bind to glycans and prevent gp120 binding to CD4+ cells. However, as proteins they present significant challenges in regard to economical production and formulation for resource-poor environments. We have synthesized water-soluble polymer CBAs that contain multiple benzoboroxole moieties. A benzoboroxole-functionalized monomer was synthesized and incorporated into linear oligomers with 2-hydroxypropylmethacrylamide (HPMAm) at different feed ratios using free radical polymerization. The benzoboroxole small molecule analogue demonstrated weak affinity for HIV-1BaL gp120 by SPR; however, the 25 mol % functionalized benzoboroxole oligomer demonstrated a 10-fold decrease in the K(D) for gp120, suggesting an increased avidity for the multivalent polymer construct. High molecular weight polymers functionalized with 25, 50, and 75 mol % benzoboroxole were synthesized and tested for their ability to neutralize HIV-1 entry for two HIV-1 clades and both R5 and X4 coreceptor tropism. All three polymers demonstrated activity against all viral strains tested with EC(50)s that decrease from 15000 nM (1500 microg mL(-1)) for the 25 mol % functionalized polymers to 11 nM (1 microg mL(-1)) for the 75 mol % benzoboroxole-functionalized polymers. These polymers exhibited minimal cytotoxicity after 24 h exposure to a human vaginal cell line.
Jay
Julie I
JI
Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City, Utah 84112-5820, USA.
Lai
Bonnie E
BE
Myszka
David G
DG
Mahalingam
Alamelu
A
Langheinrich
Kris
K
Katz
David F
DF
Kiser
Patrick F
PF
D000282:Administration, Intravaginal; D019380:Anti-HIV Agents / Q000008:administration & dosage / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D001665:Binding Sites; D001897:Boronic Acids / Q000008:administration & dosage / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000821:virology; D005260:Female; D015699:HIV Envelope Protein gp120 / Q000037:antagonists & inhibitors* / Q000737:chemistry; D015658:HIV Infections / Q000517:prevention & control; D015497:HIV-1 / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D066298:In Vitro Techniques; D008958:Models, Molecular; D015394:Molecular Structure; D011108:Polymers / Q000008:administration & dosage / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D020349:Surface Plasmon Resonance; D014621:Vagina / Q000187:drug effects / Q000821:virology; D053586:Virus Internalization / Q000187:drug effects
D019380:Anti-HIV Agents; D000890:Anti-Infective Agents; D001897:Boronic Acids; D015699:HIV Envelope Protein gp120; D011108:Polymers