2-[N1-2-pyrimidyl-aminobenzenesulfonamido] ethyl 4-bis(2-chloroethyl) aminophenyl butyrate: a potent antitumor agent

Development of sulfadiazine-decorated PLGA nanoparticles loaded with 5-fluorouracil and cell viability

The aim of this work was to synthesize sulfadiazine-poly(lactide-co-glycolide) (SUL-PLGA) nanoparticles (NPs) for the efficient delivery of 5-fluorouracil to cancer cells. The SUL-PLGA conjugation was assessed using FTIR, ¹H-NMR, ¹³C-NMR, elemental analysis and TG and DTA analysis. The SUL-PLGA NPs were characterized using transmission and scanning electron microscopy and dynamic light scattering. Additionally, the zeta potential, drug content, and in vitro 5-FU release were evaluated. We found that for the SUL-PLGA NPs, D_h = 114.0 nm, ZP = −32.1 mV and the encapsulation efficiency was 49%. The 5-FU was released for up to 7 days from the NPs. Cytotoxicity evaluations of 5-FU-loaded NPs (5-FU-SUL-PLGA and 5-FU-PLGA) on two cancer cell lines (Caco-2, A431) and two normal cell lines (fibroblast, osteoblast) were compared. Higher cytotoxicity of 5-FU-SUL-PLGA NPs were found to both cancer cell lines when compared to normal cell lines, demonstrating that the presence of SUL could significantly enhance the cytotoxicity of the 5-FU-SUL-PLGA NPs when compared with 5-FU-PLGA NPs. Thus, the development of 5-FU-SUL-PLGA NPs to cancer cells is a promising strategy for the 5-FU antitumor formulation in the future.

Passive and active hepatoma tumor targeting of new N-(2-hydroxypropyl)methacrylamide copolymer conjugates: synthesis, characterization, and evaluation in vitro and in vivo

Human hepatocellular carcinoma (HCC) is one of the major causes of death worldwide. To investigate the relative importance of active and passive targeting strategies, the synthesis, characterization, in vitro uptake, and in vivo biodistribution of specific sulfapyridine HPMA (HPMA: N-(2-hydroxypropyl methacrylamide)) copolymer (sulfapyridine: SPD) conjugates, nonspecific HPMA copolymer conjugates, and DTPA are described in this study. The poly(HPMA)-SPD-DTPA (DTPA: diethylenetriaminepentaacetic acid), poly(HPMA)-DTPA, and DTPA conjugates were radiolabeled with the radionuclide (99m)Tc and tested for uptake by cultured H22 cells. The cellular accumulation of poly(HPMA)-SPD-DTPA-(99m)Tc complex was found to be time-dependent. The poly(HPMA)-SPD-DTPA-(99m)Tc tracer exhibited rapid uptake kinetics in cell culture with a t(1/2) of ~5 min. The uptake of poly(HPMA)-SPD-DTPA-(99m)Tc was significantly higher than that of poly(HPMA)-DTPA-(99m)Tc, indicating that the uptake of the poly(HPMA)-SPD-DTPA-(99m)T was active binding. The uptake of poly(HPMA)-DTPA-(99m)Tc was significantly higher than that of DTPA-(99m)Tc, suggesting that the uptake of the poly(HPMA)-DTPA-(99m)T was passive binding. Twenty-four hour necropsy data in the hepatocellular carcinoma tumor model showed significantly higher (p < 0.001) tumor localization for poly(HPMA)-SPD-DTPA-(99m)Tc (4.98 ± 0.48%ID/g [percentage injected dose per gram tissue]) compared with poly(HPMA)-DTPA-(99m)Tc (2.69 ± 0.15% ID/g) and DTPA-(99m)Tc (0.83 ± 0.03%ID/g). Moreover, higher T/B for poly(HPMA)-SPD-DTPA-(99m)Tc indicated reduced extravazation of the targeted polymeric conjugates in normal tissues. Specific molecular targeting and nonspecific vascular permeability are both significant in the relative tumor localization of poly(HPMA)-SPD-DTPA-(99m)Tc. Extravascular leak in nonspecific organs appears to be a major factor in reducing the T/B for the sulfapyridine molecules. Thus, the poly(HPMA)-SPD-DTPA is expected to be used as the potential macromolecular targeting carrier for hepatoma carcinoma in mice.

Synthesis, characterization, and in vivo evaluation of tumor targeting N-(2-hydroxypropyl)methacrylamide copolymer conjugates containing sulfamethazine groups

Recent studies have identified that sulfadiazine derivatives can be concentrated in the hepatocellular carcinoma tissue. Herein, we report the synthesis, characterization, and evaluation of a novel sulfamethazine N-(2-hydroxypropyl)methacrylamide copolymer conjugates for tumor targeting. N-(3-Aminopropyl)methacrylamide-diethylenetriaminepentaacetic acid monomer 1, methacryloyl-sulfamethazine monomer 2, poly( N-(2-hydroxypropyl)methacrylamide)-sulfamethazine-diethylenetriaminepentaacetic acid conjugate 4, and poly( N-(2-hydroxypropyl)methacrylamide)-sulfamethazine-diethylenetriaminepentaacetic acid-99mTc were successfully synthesized and characterized. Poly( N-(2-hydroxypropyl)methacrylamide)-diethylenetriaminepentaacetic acid conjugate 3, diethylenetriaminepentaacetic acid-99mTc, and poly( N-(2-hydroxypropyl)methacrylamide)-diethylenetriaminepentaacetic acid-99mTc were also synthesized and characterized for comparison (99mTc: metastable technetium-99). A 24-h necropsy data in the hepatocellular carcinoma tumor model showed significantly higher ( p < 0.001) tumor localization for poly( N-(2-hydroxypropyl)methacrylamide)-sulfamethazine-diethylenetriaminepentaacetic acid-99mTc (4.82%ID/g ± 0.46%ID/g (percentage injected dose per gram tissue)) compared with poly( N-(2-hydroxypropyl)methacrylamide)-diethylenetriaminepentaacetic acid-99mTc (2.69%ID/g ± 0.15%ID/g) and diethylenetriaminepentaacetic acid-99mTc (0.83%ID/g ± 0.03%ID/g). Moreover, higher tumor/organ ratios for poly( N-(2-hydroxypropyl)methacrylamide)-sulfamethazine-diethylenetriaminepentaacetic acid-99mTc indicated reduced extravasation of the targeted polymeric conjugates in normal tissues. Thus, the poly( N-(2-hydroxypropyl)methacrylamide)-sulfamethazine-diethylenetriaminepentaacetic acid can potentially be used as a macromolecular targeting carrier for hepatocellular carcinoma in mice.

Synthesis and cytotoxicity of some rigid derivatives of methyl 2,5-dihydroxycinnamate

Eight rigid compounds designed as esterase-stable analogues of methyl 2,5-dihydroxycinnamate (1) were synthesized. These derivatives include 2-(2',5'-dihydroxybenzylidene)cyclopentenone (3a), 2-(2',5'-dihydroxybenzylidene)cyclohexanone (3b), 2,6-bis(2',5'-dihydroxybenzylidene)cyclohexanone (4b), 2,6-bis(2',5'-dihydroxybenzylidene)cyclopentenone (4a), (E)-3-(2',5'-dihydroxybenzylidene)pyrrolidin-2-one (5), (E)-5-(2',5'-dihydroxybenzylidene)-1,2-isothiazolidine-1,1-dioxide (6), 4-(2',5'-dihydroxyphenyl)-5H-furan-2-one (7), and 3-(2',5'-dihydroxyphenyl)cyclopent-2-ene-1-one (8). Among the eight compounds, the furanone 7 and cyclopentenone 8 showed the most potent cytotoxicity with IC50 values of 0.39-0.98 microg/mL. Compound 8 was further brominated, phenylated and methylated at the alpha position to give three corresponding analogues, including 2-bromo-3-(2',5'-dihydroxyphenyl)cyclopent-2-ene-1-one (24), 3-(2',5'-dihydroxyphenyl)-2-phenylcyclopent-2-ene-1-one (27), and 3-(2',5'-dihydroxyphenyl)-2-methylcyclopent-2-ene-1-one (28). Among the three, the most enhanced activity was observed with the phenylated compound 27.