Colorectal delivery and retention of PEGAmprenavi

Authors: Mahta Samizadeh Xiaoping Zhang Simi Gunaseelan Antoinette G Nelson Matthew S Palombo Daniel R Myers Yashveer Singh Usha Ganapathi Zoltan Szekely Patrick J Sinko

Publish Date: 2015/12/28

Volume: 6, Issue: 1, Pages: 1-16

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Abstract

Local delivery of antiHIV drugs to the colorectal mucosa a major site of HIV replication and their retention within mucosal tissue would allow for a reduction in dose administered reduced dosing frequency and minimal systemic exposure The current report describes a mucosal preexposure prophylaxis mPrEP strategy that utilizes nanocarrier conjugates NC consisting of polyethylene glycol PEG amprenavir APV and a cellpenetrating peptide CPP namely Bac7 a fragment derived from bactenecin 7 APVPEG NCs with linear PEGs 2 5 10 and 30 kDa exhibited reduced 52–21  antiHIV1 protease PR activity as compared to free APV in an enzymebased FRET assay In MT2 T cells APVPEG34 kDaFITC APF antiHIV1 activity was significantly reduced 160fold IC50 = 8064 nM due to poor cell uptake whereas it was restored IC50 = 7829 nM and similar to APV IC50 = 5029 nM with the addition of Bac7 to the NC ie APVPEG34 kDaBac7 APB Flow cytometry and confocal microscopy demonstrated Bac7PEG34 kDaFITC BPF uptake was two and fourfold higher than APF in MT2 T cells and Caco2 intestinal epithelial cells respectively There was no detectable punctate fluorescence in either cell line suggesting that BPF directly enters the cytosol thus avoiding endosomal entrapment After colorectal administration in mice BPF mucosal concentrations were 21fold higher than APF concentrations BPF concentrations also remained constant for the 5 days of the study suggesting that 1 the NC’s structural characteristics ie the size of the PEG carrier and the presence of a CPP significantly influenced tissue persistence and 2 the NCs were probably lodged in the lamina propria since the average rodent colon mucosal cell turnover time is 2–3 days These encouraging results suggest that Bac7 functionalized NCs delivered locally to the colorectal mucosa may form drug delivery depots that are capable of sustaining colorectal drug concentrations Although the exact mechanisms for tissue persistence are unclear and will require further study these results provide proofofconcept feasibility for mPrEPFinancial support from NIH MERIT AI51214 AI117776 and the ParkeDavis Endowed Chair in Pharmaceutics and Drug Delivery is gratefully acknowledged Flow cytometry/Cell sorting CORE facility at Rutgers The State University of New Jersey is acknowledged for performing flow cytometry and confocal microscopy The human CD4+ MT2 T cells were obtained from Dr Douglas Richman courtesy the NIH AIDS research and reference program division of AIDS NIAID NIH cat 237 A fellowship from the American Foundation for Pharmaceutical Education to M Palombo is also acknowledged

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