Oleate-modified hyaluronan: Controlling the number and distribution of side chains by varying the reaction conditions

In this work, low molecular weight hyaluronan was chemically modified by oleoyl moieties utilising mixed anhydrides methodology. The activation of oleic acid with benzoyl chloride in organic solvents miscible with water was followed by NMR spectroscopy. The product selectivity correlates with the solvent's Hildebrand solubility parameter. Furthermore, the effect of the solvent for the mixed anhydride formation was elucidated by density functional theory (DFT) and showed that the reactions are faster in acetonitrile or alcohols than in hexane. Furthermore, the solvent demonstrated to control the substituent distribution pattern along HA chain during esterification. An even distribution of substituents was observed in reactions performed in water mixed with ethers. The substituent distribution pattern clearly influenced the aggregation behaviour of amphiphilic HA, controlling the stability of the delivery system, while increasing the encapsulation capacity.

MOFs-Derived Fe-N Codoped Carbon Nanoparticles as O2-Evolving Reactor and ROS Generator for CDT/PDT/PTT Synergistic Treatment of Tumors

Metal-organic frameworks (MOFs) derivatives had been widely explored in electronic and environmental fields, but rarely evaluated in the biomedical applications. Herein, Fe-N codoped carbon (FeNC) nanoparticles were synthesized and characterized via facile pyrolysis of precursor ZIF-8 (Fe/Zn) nanoparticles, and their potential applications in tumor therapy were assessed in this investigation both in vitro and in vivo. After PAA (sodium polyacrylate) modification, the FeNC@PAA nanoparticles were able to initiate a Fe-based Fenton-like reaction to generate ·OH and O₂ for chemodynamic therapy (CDT) and O₂ evolution. Meanwhile, the porphyrin-like metal center in the FeNC@PAA nanoparticles could be used as a photosensitizer for photodynamic therapy (PDT) of tumors, which could be enhanced by O₂ generated in CDT. Furthermore, the FeNC@PAA nanoparticles were also found to be effective in photothermal therapy (PTT) with a photothermal conversion efficiency of 29.15%, owing to a high absorbance in the near-infrared region (NIR). In conclusion, the synthesized FeNC@PAA nanoparticles exhibited promising applications in O₂ evolution and CDT/PDT/PTT synergistic treatment of tumors.

Polymeric Drug Delivery Systems Bearing Cholesterol Moieties: A Review

This review aims to provide an overview of polymers comprising cholesterol moiety/ies designed to be used in drug delivery. Over the last two decades, there have been many papers published in this field, which are summarized in this review. The primary focus of this article is on the methods of synthesis of polymers bearing cholesterol in the main chain or as side chains. The data related to the composition, molecular weight, and molecular weight distribution of polymers are presented. Moreover, other aspects, such as forms of carriers, types of encapsulated drugs, encapsulation efficiency and capacity, are also included.

Evaluation of the Synergism Mechanism of Tamoxifen and Docetaxel by Nanoparticles

BACKGROUND

Our previous studies have shown that Docetaxel (DTX) and Tamoxifen (TMX) loaded nanoparticles(Co-NPs) could exhibit a synergistic effect on estrogen receptor positive cell lines. In the current study，we have studied the synergistic effect of Co-NPs and underlying possible molecular mechanism.

METHODS

Cell apoptosis assay, pharmacokinetic experiment and immunohistochemistry experiment were used to explore the synergistic effect and underlying possible mechanism in vitro and in vivo.

RESULTS

Cell apoptosis assay revealed that Co-NPs could mediate cell sensitization to a cytotoxic agent, resulting in remarkable cell apoptosis. In addition, pharmacokinetic experiment research showed that Co-NPs have longer circulation time in vivo, which could prolong the treatment time of the chemotherapeutic drugs. Immunohistochemistry experiment revealed that the Co-NPs could downregulate the expression of P-gp level to reduce the drugs' efflux.

CONCLUSION

The possible mechanism of the synergistic effect of DTX and TMX by Co-NPs was attributed to the longer in vivo circulation time, significantly increased rate of cell apoptosis and downregulated expression of P-gp level to the tumor cells.

Cholesterol-Based Compounds: Recent Advances in Synthesis and Applications

This review reports on the latest developments (since 2014) in the chemistry of cholesterol and its applications in different research fields. These applications range from drug delivery or bioimaging applications to cholesterol-based liquid crystals and gelators. A brief overview of the most recent synthetic procedures to obtain new cholesterol derivatives is also provided, as well as the latest anticancer, antimicrobial, and antioxidant new cholesterol-based derivatives. This review discusses not only the synthetic details of the preparation of new cholesterol derivatives or conjugates, but also gives a short summary concerning the specific application of such compounds.

Metal-Organic Framework as a Microreactor for in Situ Fabrication of Multifunctional Nanocomposites for Photothermal-Chemotherapy of Tumors in Vivo

Metal-organic frameworks (MOFs) have been applied in chemotherapeutic drug loading for cancer treatment, but challenging for cases with large and malignant lesions. To overcome these difficulties, combinational therapies of chemotherapy and photothermal therapy (PTT) with potentially high selectivity and slight aggressiveness have drawn tremendous attention to treat various tumors. However, current MOF-based nanohybrids with photothermal agents involve tedious synthesis processes and heterogeneous structures. Herein, we employ MIL-53 as a microreactor to grow polypyrrole (PPy) nanoparticles in situ for the fabrication of PPy@MIL-53 nanocomposites. Fe³⁺ in MIL-53, as an intrinsic oxidizing agent, can oxidize the pyrrole monomer to generate PPy nanoparticles. The prepared PPy@MIL-53 nanocomposites integrate the intrinsic advantages of MOFs with high drug loading ability and magnetic resonance imaging (MRI) capacity, and PPy nanoparticles with outstanding PTT ability and excellent biocompatibility. The versatile PPy@MIL-53 nanocomposites with multiple functions displayed in vitro and in vivo synergism of photothermal-chemotherapy for cancer, potentially MRI-guided. The proposed MOF microreactor-based synthesis strategy shows a promising prospect in the fabrication of diverse multifunctional nanohybrids for tumor theranostics in vivo.

Fabrication of a hyaluronic acid conjugated metal organic framework for targeted drug delivery and magnetic resonance imaging

Since metal organic frameworks (MOF) have exhibited fascinating potential in biomedical applications, it is worthwhile to construct a MOF-based multifunctional drug delivery system. In the present study, the anticancer drug doxorubicin (DOX) was loaded into zeolitic imidazolate framework-8 (ZIF-8) via a one-pot process. The formed DOX@ZIF-8 was then coated with polydopamine, successively chelated with Fe3+ and conjugated with hyaluronic acid (HA), finally resulting in a multifunctional ZIF-8 nanocarrier. The characterization results confirmed the successful formation of the hybrid nanocarrier. pH-responsive drug release of DOX was observed due to the innate pH-dependent stability of ZIF-8. Importantly, the flow cytometry and confocal laser scanning microscope results both verified the targeting ability of DOX@ZIF-HA toward prostate cancer PC-3 cells. The improved therapeutic efficacy of DOX@ZIF-HA when compared to the inhibited group was also demonstrated. Furthermore, the chelation of Fe3+ by PDA makes the prepared DOX@ZIF-HA a good contrast agent for magnetic resonance (MR) imaging. Hence, we hope the constructed ZIF-8 based multifunctional nanocarrier could be a candidate for cancer theranostics.