ROS-Generating Poly(Ethylene Glycol)-Conjugated Fe3O4 Nanoparticles as Cancer-Targeting Sustained Release Carrier of Doxorubicin.

Purpose: Site-specific drug delivery systems can contribute to the development and execution of effective cancer treatment. Due to its favorable features (including high biocompatibility, high hydrophilicity and ease of functionalization), poly(ethylene glycol) (PEG) has been widely adopted to design drug carriers. Generating carriers for delivery of hydrophobic anticancer agents, however, is still a challenge in carrier design. Methods: In the first step, PEG is functionalized with dialdehyde to generate PEG-(CHO)2 using EDC/NHS chemistry. In the second step, Fe3O4 nanoparticles are functionalized with amino groups to generate Fe3O4-NH2. In the third step, PEG-(CHO)2, Fe3O4-NH2 and doxorubicin (DOX) react in an acidic environment to yield a drug conjugate (PEGDA-MN-DOX), which is subsequently characterized by FT-IR, 1H-NMR, SEM, TEM, DLS, TGA, and DSC. Results: The chemical functionalities of the drug conjugate are confirmed by FTIR, H-NMRand XRD analysis.The release pattern of PEGDA-MN-DOX is investigated at 25 and 37 °C at different pH values. The results indicate that the developed drug conjugate cannot only behave as a sustained-release carrier, but can also generate a significant level of reactive oxygen species (ROS), leading to a high level of toxicity against MCF-7 cells while still showing excellent biocompatibility in 3T3 cells. Conclusion: The reported conjugate shows anticancer potential, cancer-targeting ability, and ROS-generating capacity for effective drug encapsulation and sustained release in chemotherapy.

Synthesis of Novel Tamarind Gum-co-poly(acrylamidoglycolic acid)-Based pH Responsive Semi-IPN Hydrogels and Their Ag Nanocomposites for Controlled Release of Chemotherapeutics and Inactivation of Multi-Drug-Resistant Bacteria.

In this paper, novel pH-responsive, semi-interpenetrating polymer hydrogels based on tamarind gum-co-poly(acrylamidoglycolic acid) (TMGA) polymers were synthesized using simple free radical polymerization in the presence of bis[2-(methacryloyloxy)ethyl] phosphate as a crosslinker and potassium persulfate as a initiator. In addition, these hydrogels were used as templates for the green synthesis of silver nanoparticles (13.4 ± 3.6 nm in diameter, TMGA-Ag) by using leaf extract of Teminalia bellirica as a reducing agent. Swelling kinetics and the equilibrium swelling behavior of the TMGA hydrogels were investigated in various pH environments, and the maximum % of equilibrium swelling behavior observed was 2882 ± 1.2. The synthesized hydrogels and silver nanocomposites were characterized via UV, FTIR, XRD, SEM and TEM. TMGA and TMGA-Ag hydrogels were investigated to study the characteristics of drug delivery and antimicrobial study. Doxorubicin hydrochloride, a chemotherapeutic agent successfully encapsulated with maximum encapsulation efficiency, i.e., 69.20 ± 1.2, was used in in vitro release studies in pH physiological and gastric environments at 37 °C. The drug release behavior was examined with kinetic models such as zero-order, first-order, Higuchi, Hixson Crowell and Korsmeyer-Peppas. These release data were best fitted with the Korsemeyer-Peppas transport mechanism, with n = 0.91. The effects of treatment on HCT116 human colon cancer cells were assessed via cell viability and cell cycle analysis. The antimicrobial activity of TMGA-Ag hydrogels was studied against Staphylococcus aureus and Klebsiella pneumonia. Finally, the results demonstrate that TMGA and TMGA-Ag are promising candidates for anti-cancer drug delivery and the inactivation of pathogenic bacteria, respectively.