ABSTRACT
The preclinical development of peptidyl drugs for cancer treatment is hampered by their poor pharmacologic properties and cell penetrative capabilities in vivo. In this study, we report a nanoparticle-based formulation that overcomes these limitations, illustrating their utility in studies of the anticancer peptide NuBCP-9, which converts BCL-2 from a cell protector to a cell killer. NuBCP-9 was encapsulated in polymeric nanoparticles composed of a polyethylene glycol (PEG)-modified polylactic acid (PLA) diblock copolymer (NuBCP-9/PLA-PEG) or PEG-polypropylene glycol-PEG-modified PLA-tetrablock copolymer (NuBCP-9/PLA-PEG-PPG-PEG). We found that peptide encapsulation was enhanced by increasing the PEG chain length in the block copolymers. NuBCP-9 release from the nanoparticles was controlled by both PEG chain length and the PLA molecular weight, permitting time-release over sustained periods. Treatment of human cancer cells with these nanoparticles in vitro triggered apoptosis by NuBCP-9-mediated mechanism, with a potency similar to NuBCP-9 linked to a cell-penetrating poly-Arg peptide. Strikingly, in vivo administration of NuBCP-9/nanoparticles triggered complete regressions in the Ehrlich syngeneic mouse model of solid tumor. Our results illustrate an effective method for sustained delivery of anticancer peptides, highlighting the superior qualities of the novel PLA-PEG-PPG-PEG tetrablock copolymer formulation as a tool to target intracellular proteins.
Subject(s)
Antineoplastic Agents/pharmacology , Carcinoma, Ehrlich Tumor/drug therapy , Nanocapsules/chemistry , Oligopeptides/pharmacology , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/metabolism , Apoptosis , Carcinoma, Ehrlich Tumor/pathology , Cell Proliferation/drug effects , Delayed-Action Preparations/chemistry , Delayed-Action Preparations/metabolism , Delayed-Action Preparations/pharmacology , Drug Screening Assays, Antitumor , Hep G2 Cells , Humans , Inhibitory Concentration 50 , Lactates/chemistry , MCF-7 Cells , Mice , Mice, Inbred BALB C , Neoplasm Transplantation , Oligopeptides/chemistry , Oligopeptides/metabolism , Particle Size , Polyethylene Glycols/chemistry , Propylene Glycols/chemistry , Proto-Oncogene Proteins c-bcl-2/metabolism , Tumor Burden/drug effectsABSTRACT
BACKGROUND: Stability is considered the most important parameter before performing any melanocyte transplantation procedure in vitiligo; however, current criteria rely on the history given by the patients. OBJECTIVE: This study was undertaken to determine the clinical, biochemical and immunological factors determining stability of disease in patients with generalized vitiligo to facilitate better patient selection for melanocyte transplantation and to understand immunological mechanisms for disease activity. METHODS: Thirty-three patients with generalized vitiligo with < 10% body surface area involved were allocated to three clinical stability groups: Group 1 (stability > 3 months but < 1 year), Group 2 (≥ 1 year but < 2 years) and Group 3 (≥ 2 years). Melanocyte transplantation was done using suction blister epidermal grafting (SBEG) on a single patch. Blood was drawn for catalase estimation from all patients and from 10 healthy control subjects. A 3-mm punch biopsy was taken on the day of transplantation from the margin of the macule in the first five patients in each group for the immunohistochemistry of CD4, CD8, CD45RO, CD45RA and FoxP3. Those with ≥ 75% repigmentation at 6 months were labelled as responders. RESULTS: The success rate was 0% in Group 1, 37·5% in Group 2 and 77·8% in Group 3. The difference in the success rate between the groups was statistically significant (P = 0·005). The median period of stability was significantly higher in the responders compared with that in the nonresponders (P = 0·001). Catalase levels were not significantly different between patients in the three groups of cases and in controls, or between responders and nonresponders. Lesional CD8 cells were significantly higher in Group 1 compared with Group 3. The percentages of CD8 and CD45RO cells were significantly higher in the nonresponders compared with the responders. CONCLUSION: Along with clinical stability, the proportion of CD8 and CD45RO cells in skin biopsies might help to determine the stability of the disease and thereby predict the success of transplantation.
Subject(s)
Melanocytes/transplantation , Vitiligo/therapy , Adolescent , Adult , Aged , Catalase/metabolism , Female , Humans , Immunohistochemistry , Leukocyte Common Antigens/immunology , Male , Middle Aged , T-Lymphocytes/immunology , Treatment Outcome , Vitiligo/enzymology , Vitiligo/immunology , Young AdultABSTRACT
BACKGROUND: Gold nanorods show a surface plasmon resonance (SPR) band at the near infra-red (NIR) region which enables them to produce heat on irradiation with a NIR laser. As a result of this, gold nanorods have the potential to be used as thermal therapeutic agents for selective damage to cancer cells, bacterial cells, viruses, and DNA. METHODS: Gold nanorods with an aspect ratio of approximately 5 were prepared by exploiting the normal micellar route of a water/dioctyl sulfosuccinate (Aerosol-T)/hexane system. The shape and size of the gold nanorods were characterized by surface plasmon bands at 520 nm and 980 nm, and by atomic force microscopy and transmission electron microscopy. RESULTS: The length of the gold nanorods was 100 nm and their diameter was 20 nm. X-ray diffraction analysis demonstrated that the gold nanorods formed were metallic in nature. The gold nanorods showed good photothermolysis activity. CONCLUSION: Gold nanorods injected subcutaneously and irradiated with 980 nm laser caused injury to rat tissue, demonstrating that gold nanorods may be used to kill cancerous cells in tumor tissue.
