Boronated protoporphyrin (BOPP): localization in lysosomes of the human glioma cell line SF-767 with uptake modulated by lipoprotein levels

Chiral porphyrazine near-IR optical imaging agent exhibiting preferential tumor accumulation

“…Hydrophobic tetrapyrroles accumulate in cells through a variety of mechanisms, including passive diffusion, entry by flipping through the membrane, and association with serum proteins (11,26). Serum components, including albumin and LDL, have been shown to act as delivery vehicles for hydrophobic compounds through receptordependent and independent endocytosis, both leading to lysosomal accumulation (26)(27)(28). To determine whether uptake of 247 is associated with serum components, MDA-MB-231 breast tumor cells were incubated with 247 in complete media ( Fig.…”

Synthetic nano-low density lipoprotein as targeted drug delivery vehicle for glioblastoma multiforme

“…The epidermal growth factor receptor (Barth et al, 2002), platelet derived growth factor receptor (Hermanson et al, 1992), fibroblast growth factor receptor (Morrison et al, 1994), human epidermal receptor type 2 (Mineo et al, 2004), and interleukin-13 receptor (Mintz et al, 2002) have been shown to be upregulated in glioma cells. We have previously shown that human GBM cell lines express high levels of LDL receptors (Maletinska et al, 2000) and demonstrated that boronated protoporphryn is delivered to the SF-767 GBM cell line by LDL (Callahan et al, 1999). LDL receptors are sparse in normal brain tissue (Pitas et al, 1987) suggesting that the LDL receptor represents a unique target that can be used for delivery of chemotherapeutics targeted to tumor cells.…”

“…Previously described GBM cells lines (SF-767, U-251, SF-763) were obtained from the tissue bank of the Brain Tumor Research Center (University of California San Francisco, CA) (Callahan et al, 1999). GBM cells were grown, 37°C, 5% CO 2 , essentially as described by Callahan et al (1999) For confocal microscopy, cells were plated at 2x10 4 cells on a polylysine coated coverslip in a 24-well plate.…”

“…GBM cells were grown, 37°C, 5% CO 2 , essentially as described by Callahan et al (1999) For confocal microscopy, cells were plated at 2x10 4 cells on a polylysine coated coverslip in a 24-well plate. Cells were allowed to grow for 48 h before lipoprotein-deficient fetal bovine serum (LPDS) in above MEM was placed on the cells (Callahan et al, 1999). Experiments were conducted on exponentially growing cells, at approximately 70% confluency, 24 h after addition of LPDS media.…”

“…It was previously suggested that plasma-derived LDL could be used as a drug delivery system for tumors expressing LDLR since its hydrophobic core has the possibility of incorporating lipophilic drugs (Firestone, 1994, Rensen et al, 2001. Drugs have been either directly loaded onto plasma LDL or the core lipids of LDL were replaced with drugs (Callahan et al, 1999, Ji et al, 2002, Chu et al, 2001, Vitols et al, 1985, Firestone et al, 1984, Dubowchik and Firestone, 1995, Vitols et al, 1990. Plasma LDL, however, is less than ideal as a targeting agent since it is difficult to isolate in large quantities and is variable in composition and size.…”