Docetaxel-tethered di-Carboxylic Acid Derivatised Fullerenes: A Promising Drug Delivery Approach for Breast Cancer.

Docetaxel (DTX) has become widely accepted as a first-line treatment for metastatic breast cancer; however, the frequent development of resistance provides challenges in treating the disease.C60 fullerene introduces a unique molecular form of carbon, exhibiting attractive chemical and physical properties. Our study aimed to develop dicarboxylic acid-derivatized C60 fullerenes as a novel DTX delivery carrier. This study investigated the potential of water-soluble fullerenes to deliver the anti-cancer drug DTX through a hydrophilic linker. The synthesis was carried out using the Prato reaction. The spectroscopic analysis confirmed the successful conjugation of DTX molecules over fullerenes. The particle size of nanoconjugate was reported to be 122.13 ± 1.63 nm with a conjugation efficiency of 76.7 ± 0.14%. The designed conjugate offers pH-dependent release with significantly less plasma pH, ensuring maximum release at the target site. In-vitro cell viability studies demonstrated the enhanced cytotoxic nature of the developed nanoconjugate compared to DTX. These synthesized nanoscaffolds were highly compatible with erythrocytes, indicating the safer intravenous route administration. Pharmacokinetic studies confirmed the higher bioavailability (~ 6 times) and decreased drug clearance from the system vis-à-vis plain drug. The histological studies reveal that nanoconjugate-treated tumour cells exhibit similar morphology to normal cells. Therefore, it was concluded that this developed formulation would be a valuable option for clinical use.

Novel trastuzumab-DM1 conjugate: Synthesis and bio-evaluation.

Antibody-drug conjugates are now of considerable interest and are recommended for the treatment of cancers. Linkers are having a crucial role in potency and efficacy of these drugs. Herein, for the first time, we have used a water-soluble poly-ethylene glycol based linker (succinimidyl-[(N-maleimido propionamido)-diethyleneglycol] [SM(PEG)2]) for lysine amide coupling of DM1 drug to trastuzumab considering evaluation of the effect of using a hydrophilic linker on physicochemical and biological properties of the resulting conjugate in comparison to the conjugate containing succinimidyl 4-(N-maleimidomethyl) cyclohexane-1-carboxylate (SMCC) linker, which has a relative hydrophobic nature. The physicochemical properties of synthesized conjugates were investigated in terms of drug to antibody ratio, size variants and free drug quantities. In vitro biological activity of trastuzumab-DM1 conjugates was assessed on breast cancer cell lines expressing different levels of HER2 using binding affinity, antiproliferative, apoptosis, and antibody-dependent cell-mediated cytotoxicity (ADCC) assays. Synthesized conjugate containing hydrophilic linker, showed higher drug to antibody ratio, no aggregated form and higher cellular toxicity in comparison to SMCC bearing conjugate. Binding affinity and ADCC potential of conjugates was not affected upon the usage of hydrophilic linker. In conclusion, application of SM(PEG)2 for coupling of DM1 to trastuzumab enhance desirable characteristics of the resulting conjugate.

Radiofluorinated GPC3-Binding Peptides for PET Imaging of Hepatocellular Carcinoma.

PURPOSE: Hepatocellular carcinoma (HCC) remains one of the most challenging diseases worldwide. Glypican-3 (GPC-3) is a cell surface proteoglycan that is overexpressed on the membrane of HCC cells. The purpose of this study was to develop a target-specific radiofluorinated peptide for positron emission tomography (PET) imaging of GPC3 expression in hepatocellular carcinoma. PROCEDURES: New GPC3-binding peptides (GP2076 and GP2633) were radiolabeled with F-18 using Al[18F]F labeling approach, and the resulting PET probes were subsequently subject to biological evaluations. A highly hydrophilic linker was incorporated into GP2633 with an aim of reducing the probe uptake in liver and increasing tumor-to-liver (T/L) contrast. Both GP2076 and GP2633 were radiolabeled using Al[18F]F chelation approach. The binding affinity, octanol/water partition coefficient, cellular uptake and efflux, and stability of both F-18 labeled peptides were tested. Tumor targeting efficacy and biodistribution of Al[18F]F-GP2076 and Al[18F]F-GP2633 were determined by PET imaging in HCC-bearing mice. Immunohistochemistry analyses were performed to compare the findings from PET scans. RESULTS: Al[18F]F-GP2076 and Al[18F]F-GP2633 were rapidly radiosynthesized within 20 min in excellent radiochemical purity (> 97 %). Al[18F]F-GP2633 was determined to be more hydrophilic than Al[18F]F-GP2076 in terms of octanol/water partition coefficient. Both Al[18F]F-GP2076 and Al[18F]F-GP2633 demonstrated good in vitro and in vivo stability and binding specificity to GPC3-positive HepG2 cells. For PET imaging, Al[18F]F-GP2633 exhibited enhanced uptake in HepG2 tumor (%ID/g 3.37 ± 0.35 vs. 2.13 ± 0.55, P = 0.031) and reduced accumulation in liver (%ID/g 1.70 ± 0.26 vs. 3.70 ± 0.98, P = 0.027) at 60 min post-injection (pi) as compared to Al[18F]F-GP2076, resulting in significantly improved tumor-to-liver (T/L) contrast (ratio 2.00 ± 0.18 vs. 0.59 ± 0.14, P = 0.0004). Higher uptake of Al[18F]F-GP2633 in GPC3-positive HepG2 tumor was observed as compared to GPC3-negative McA-RH7777 tumor (%ID/g 3.37 ± 0.35 vs. 1.64 ± 0.03, P = 0.001) at 60 min pi, confirming GPC3-specific accumulation of Al[18F]F-GP2633 in HepG2 tumor. CONCLUSION: The results demonstrated that Al[18F]F-GP2633 is a promising probe for PET imaging of GPC3 expression in HCC. Convenient preparation, excellent GPC3 specificity in HCC, and favorable excretion profile of Al[18F]F-GP2633 warrant further investigation for clinical translation. PET imaging with a GPC3-specific probe would provide clinicians with vital diagnostic information that could have a significant impact on the management of HCC patients.

Antibacterial cotton fabrics based on hydrophilic amino-containing scaffolds.

A hydrophilic amino compound, 4,7,10-trioxatridecane-1,13-diamine, has been utilized in several chemical and biochemical studies. Among previous applications is its use as a flexible and economical spacer molecule to increase the length between two moieties of interest, one of which may be a solid-phase interface. In this study, we immobilized this molecule on cotton fabrics and showed that this modified surface (DA) exhibited significant antibacterial activities in both Gram-negative bacteria and a Gram-positive bacterium. Studies on the structure-activity relationship revealed that additional chemical modifications on DA usually led to lowered antibacterial activities, emphasizing an importance of having free amino groups. Further investigation by fluorescence microscope indicated that this modified surface likely interfered with the membrane integrity of bacteria, leading to cell lysis. In addition, this scaffold was also tested for its biocompatibility with mouse fibroblast cells, and exerted no detrimental effect to the cell growth, highlighting its potential as a practical antibacterial surface modifier.