Photosensitiser-loaded biodegradable polymeric micelles: Preparation, characterisation and in vitro PDT efficacy

@article{citeulike:2522225, abstract = {The application of photosensitisers (PSs) in photodynamic therapy (PDT) is often hampered by their hydrophobicity, as this complicates their formulation and results in an unfavourable biodistribution. Consequently, there is an urgent need for novel delivery vehicles for PSs. In this paper, the loading and stability of thermosensitive mPEG-b-p(HPMAm-Lac2) micelles with a hydrophobic solketal-substituted phthalocyanine (Si(sol)2Pc) photosensitiser were studied. It was shown that the Si(sol)2Pc could be loaded efficiently in the micelles (diameter 75 nm) up to a concentration of ~ 2 mg/mL. UV/Vis and fluorescence spectroscopy showed that at low concentrations (<= 0.05 [mu]M, 0.45 mg/mL polymer), the PS was molecularly dissolved in the micellar core, whereas it was present in an aggregated form at higher concentrations. In B16F10 and 14C cells, the photocytotoxicity of Si(sol)2Pc-loaded micelles (PS < 0.05 [mu]M) was similar to free PS, i.e. IC50 of 3.0 +/- 0.2 nM (10\% serum). The cellular uptake of high-loaded micelles (10 [mu]M Si(sol)2Pc) was low and independent of the serum concentration. The nanoaggregates of Si(sol)2Pc loaded in the micellar core were only released upon hydrolysis-induced micellar dissociation, which was observed after 5.5 h at pH 8.7 at 37 [degree sign]C. The stability of the high-loaded micellar Si(sol)2Pc formulation also in the presence of serum, the controlled release of the PS upon micellar disintegration and the high photodynamic activity of Si(sol)2Pc make these micelles interesting for future in vivo studies.}, author = {Rijcken, Cristianne J. and Hofman, Jan-Willem and van Zeeland, Femke and Hennink, Wim E. and van Nostrum, Cornelus F. }, citeulike-article-id = {2522225}, doi = {10.1016/j.jconrel.2007.09.002}, journal = {Journal of Controlled Release}, keywords = {biodegradable, citedby, invitro, micelles, pdt, photodynamic, photosensitizers, therapy}, month = {December}, number = {3}, pages = {144--153}, posted-at = {2008-03-12 19:01:21}, priority = {2}, title = {Photosensitiser-loaded biodegradable polymeric micelles: Preparation, characterisation and in vitro PDT efficacy}, url = {http://dx.doi.org/10.1016/j.jconrel.2007.09.002}, volume = {124}, year = {2007} }

TY - JOUR ID - citeulike:2522225 L3 - citeulike-article-id:2522225 TI - Photosensitiser-loaded biodegradable polymeric micelles: Preparation, characterisation and in vitro PDT efficacy JF - Journal of Controlled Release VL - 124 IS - 3 SP - 144 EP - 153 N2 - The application of photosensitisers (PSs) in photodynamic therapy (PDT) is often hampered by their hydrophobicity, as this complicates their formulation and results in an unfavourable biodistribution. Consequently, there is an urgent need for novel delivery vehicles for PSs. In this paper, the loading and stability of thermosensitive mPEG-b-p(HPMAm-Lac2) micelles with a hydrophobic solketal-substituted phthalocyanine (Si(sol)2Pc) photosensitiser were studied. It was shown that the Si(sol)2Pc could be loaded efficiently in the micelles (diameter 75 nm) up to a concentration of ~ 2 mg/mL. UV/Vis and fluorescence spectroscopy showed that at low concentrations (<= 0.05 [mu]M, 0.45 mg/mL polymer), the PS was molecularly dissolved in the micellar core, whereas it was present in an aggregated form at higher concentrations. In B16F10 and 14C cells, the photocytotoxicity of Si(sol)2Pc-loaded micelles (PS < 0.05 [mu]M) was similar to free PS, i.e. IC50 of 3.0 +/- 0.2 nM (10% serum). The cellular uptake of high-loaded micelles (10 [mu]M Si(sol)2Pc) was low and independent of the serum concentration. The nanoaggregates of Si(sol)2Pc loaded in the micellar core were only released upon hydrolysis-induced micellar dissociation, which was observed after 5.5 h at pH 8.7 at 37 [degree sign]C. The stability of the high-loaded micellar Si(sol)2Pc formulation also in the presence of serum, the controlled release of the PS upon micellar disintegration and the high photodynamic activity of Si(sol)2Pc make these micelles interesting for future in vivo studies. KW - biodegradable KW - citedby KW - invitro KW - micelles KW - pdt KW - photodynamic KW - photosensitizers KW - therapy AU - Rijcken, Cristianne AU - Hofman, Jan-Willem AU - van Zeeland, Femke AU - Hennink, Wim AU - van Nostrum, Cornelus PY - 2007/12/20/ UR - http://dx.doi.org/10.1016/j.jconrel.2007.09.002 ER -