No abstract

Magnetic liposome-mediated combined chemotherapy and hyperthermia is gaining importance as an effective therapeutic modality for cancer. However, control and maintenance of optimum hyperthermia are major challenges in clinical settings due to the overheating of tissues. To overcome this problem, we developed a novel magnetic liposomes formulation co-entrapping a dextran coated biphasic suspension of LaSrMnO (LSMO) and iron oxide (FeO) nanoparticles for self-controlled hyperthermia and chemotherapy. However, the general apprehension about biocompatibility and safety of the newly developed formulation needs to be addressed. In this work, in vitro and in vivo biocompatibility and therapeutic evaluation studies of the novel magnetic liposomes are reported. Biocompatibility study of the magnetic liposomes formulation was carried out to evaluate the signs of preliminary systemic toxicity, if any, following intravenous administration of the magnetic liposomes in Swiss mice. Therapeutic efficacy of the magnetic liposomes formulation was evaluated in the fibrosarcoma tumour bearing mouse model. Fibrosarcoma tumour-bearing mice were subjected to hyperthermia following intratumoral injection of single or double doses of the magnetic liposomes with or without chemotherapeutic drug paclitaxel. Hyperthermia (three spurts, each at 3 days interval) with drug loaded magnetic liposomes following single dose administration reduced the growth of tumours by 2.5 fold (mean tumour volume 2356 ± 550 mm) whereas the double dose treatment reduced the tumour growth by 3.6 fold (mean tumour volume 1045 ± 440 mm) compared to their corresponding control (mean tumour volume 3782 ± 515 mm). At the end of the tumour efficacy studies, the presence of MNPs was studied in the remnant tumour tissues and vital organs of the mice. No significant leaching or drainage of the magnetic liposomes during the study was observed from the tumour site to the other vital organs of the body, suggesting again the potential of the novel magnetic liposomes formulation for possibility of developing as an effective modality for treatment of drug resistant or physiologically vulnerable cancer.

We report in vivo evaluation of a thermo-responsive poly(N-isopropylacrylamide)-chitosan based magnetic nanohydrogel (MNHG) incorporated with Fe 3 O 4 nanoparticles (NPs) in mice models with expandible scope for use in localized delivery of chemotherapeutics. Biocompatibility and biodistribution of the MNHG are studied in normal Swiss mice while efficacy in tumor growth inhibition is studied in a subcutaneous fibrosarcoma tumor. The ex vivo time-dependent pattern of accumulated MNHG into vital organs; lung, liver, spleen, kidney and brain collected at 1 h, 48 h, 7 d and 14 d post intravenous administration are investigated using both a vibrating sample magnetometer (VSM) and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) method. The doses of MNHG (dose I ∼ 650 and dose II ∼ 325 μg g −1 body wt) used in the study are determined based on induced thermal activation of MNHG under an AC magnetic field (AMF). Fibrosarcoma tumor bearing mice are subjected to hyperthermia with a field of 325 Oe and 265 kHz for 30 min following intratumoral administration of dose I. Tumor size measured at an interval of 72 h for a period of 2 weeks reveals that the NPs mediated therapy decelerated the growth of the transplanted tumor by about three-fold (size, 1545 ± 720 mm 3 ) as compared to the exponential growth of the tumor (size, 4510 ± 735 mm 3 ) in control mice. These results suggest the feasibility of using poly(NIPAAm)-chitosan hydrogels loaded with NPs for combined thermo-chemotherapy where the efficacy may further be improved by temperature dependent release of the drugs from the magneto hydrogels. † Electronic supplementary information (ESI) available: ESI appended with the manuscript contains FT-IR and XRD of the materials in detail. It further discusses the protocol for CBC and serum biochemistry analysis; the extended study for platelet count; differential leukocyte count, MCH and MCV as a part of CBC. H & E stained histological tissue sections of vital organs and tumor surface temperature recorded at multiple points following administration of MNHG and AMF exposure. See

No abstract

No abstract

No abstract

No abstract

No abstract