New Generation Nanomedicines Constructed from Self-Assembling Small-Molecule Prodrugs Alleviate Cancer Drug Toxicity

pH-sensitive tangeretin-ZnO quantum dots exert apoptotic and anti-metastatic effects in metastatic lung cancer cell line

Most cancer patients die as a consequence of distant metastases, which are frequently unresponsive to cancer therapy. This study focuses on the anti-tumorigenic and anti-metastatic properties of tangeretin-zinc oxide quantum dots (Tan-ZnO QDs) against the NCI-H358 cell line. Tan-ZnO QDs are pH-sensitive and capitalize on the acidic pH maintained in the tumor microenvironment; therefore, targeted drug delivery is directed specifically to cancer cells, leaving the normal cells less affected. Tan was loaded into synthesized ZnO QDs, and drug loading was analyzed using Fourier transform infrared (FTIR) spectroscopy and ultraviolet-visible (UV-Vis) spectrometry. Crystalline phase and particle size were measured using transmission electron microscopy (TEM) and X-ray diffraction (XRD). Drug release was evaluated in buffered solutions with differing pH for up to 15 h. The results confirmed stable drug release (80%) in an acidic pH. Tan-ZnO QDs induced significant cytotoxicity in NCI-H358 metastatic cells, while not markedly affecting HK-2 human normal cells. Morphology of treated H358 cells analyzed via atomic force microscopy (AFM) showed an increased surface roughness and pores. Further, the number of terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive cells increased after treatment with Tan-ZnO QDs. DNA fragmentation was also induced after treatment with increasing concentrations of Tan-ZnO QDs in H358 cells. We also confirmed regulation of apoptosis via expression levels of Bax and Bcl-2 proteins; G2/M phase cell cycle arrest was observed. Additionally, cell proliferation and migration drastically decreased, and cell invasion and migration, hallmarks of metastasis, were significantly inhibited in H358 cells. Matrix metalloproteinase (MMP)2 and MMP9, markers of metastasis, as well as vascular endothelial growth factor (VEGF), a marker of angiogenesis, were significantly downregulated upon treatment with Tan-ZnO QDs. In conclusion, our novel formulation destabilized H358 cells by using its acidic tumor microenvironment, thereby regulating cell apoptosis, proliferation, and metastatic properties.

Self-Assembling Myristoylated Human α-Defensin 5 as a Next-Generation Nanobiotics Potentiates Therapeutic Efficacy in Bacterial Infection

The increasing prevalence of antibacterial resistance globally underscores the urgent need to the update of antibiotics. Here, we describe a strategy for inducing the self-assembly of a host-defense antimicrobial peptide (AMP) into nanoparticle antibiotics (termed nanobiotics) with significantly improved pharmacological properties. Our strategy involves the myristoylation of human α-defensin 5 (HD5) as a therapeutic target and subsequent self-assembly in aqueous media in the absence of exogenous excipients. Compared with its parent HD5, the C-terminally myristoylated HD5 (HD5-myr)-assembled nanobiotic exhibited significantly enhanced broad-spectrum bactericidal activity in vitro. Mechanistically, it selectively killed Escherichia coli ( E. coli) and methicillin-resistant Staphylococcus aureus (MRSA) through disruption of the cell wall and/or membrane structure. The in vivo results further demonstrated that the HD5-myr nanobiotic protected against skin infection by MRSA and rescued mice from E. coli-induced sepsis by lowering the systemic bacterial burden and alleviating organ damage. The self-assembled HD5-myr nanobiotic also showed negligible hemolytic activity and substantially low toxicity in animals. Our findings validate this design rationale as a simple yet versatile strategy for generating AMP-derived nanobiotics with excellent in vivo tolerability. This advancement will likely have a broad impact on antibiotic discovery and development efforts aimed at combating antibacterial resistance.

Polylactide-tethered prodrugs in polymeric nanoparticles as reliable nanomedicines for the efficient eradication of patient-derived hepatocellular carcinoma

Nanomedicines have been extensively explored for cancer treatment, and their efficacies have arguably been proven in various cancer cell-derived xenograft (CDX) mouse models. However, they generally fail to show such therapeutic advantages in patients because of the huge pathological differences between human tumors and CDX models. Methods: In this study, we fabricated colloidal ultrastable nanomedicines from polymeric prodrugs and compared the therapeutic efficacies in hepatocellular carcinoma (HCC) CDX and clinically relevant patient-derived xenograft (PDX) mouse models, which closely mimic human tumor pathological properties. Working towards this goal, we esterified a highly potent SN38 (7-ethyl-10-hydroxycamptothecin) agent using oligo- or polylactide (oLA or PLA) segments with varying molecular weights. Results: The resulting SN38 conjugates assembled with polyethylene glycol-block-polylactic acid to form systemically injectable nanomedicines. With increasing PLA chain length, the SN38 conjugates showed extended retention in the nanoparticles and superior antitumor activity, completely eradicating xenografted tumors in both mouse models. Our data implicate that these small-sized and ultrastable nanomedicines might also efficaciously treat cancer in patients. More interestingly, the systemically delivered nanomedicines notably alleviated the incidence of bloody diarrhea. Conclusion: Our studies demonstrate that the appropriate molecular editing of anticancer drugs enables the generation of better tolerated cytotoxic nanotherapy for cancer, which represents a potentially useful scaffold for further clinical translation.

A nanomedicine approach enables co-delivery of cyclosporin A and gefitinib to potentiate the therapeutic efficacy in drug-resistant lung cancer

Drug resistance, accounting for therapeutic failure in the clinic, remains a major challenge to effectively manage cancer. Cyclosporin A (CsA) can reverse multidrug resistance (MDR), especially resistance to epidermal growth factor receptor tyrosine kinase inhibitors. However, the application of both drugs in cancer therapies is hampered by their poor aqueous solubility and low bioavailability due to oral administration. CsA augments the potency of gefitinib (Gef) in both Gef-sensitive and Gef-resistant cell lines. Here, we show that the simultaneous encapsulation of CsA and Gef within polyethylene glycol-block-poly(_{D, L}-lactic acid) (PEG-PLA) produced a stable and systemically injectable nanomedicine, which exhibited a sub-50-nm diameter and spherical structures. Impressively, the co-delivery of therapeutics via single nanoparticles (NPs) outperformed the oral administration of the free drug combination at suppressing tumor growth. Furthermore, in vivo results indicated that CsA formulated in NPs sensitized Gef-resistant cells and Gef-resistant tumors to Gef treatment by inactivating the STAT3/Bcl-2 signaling pathway. Collectively, our nanomedicine approach not only provides an alternative administration route for the drugs of choice but also effectively reverses MDR, facilitating the development of effective therapeutic modalities for cancer.

Injection of nanoparticles containing the anticancer drug gefitinib and the immunosuppressant cyclosporin A reverses drug-resistant cancer growth in mice. The development of multidrug resistance is the main reason why many forms of chemotherapy fail. Cyclosporin A, a drug used to prevent immune rejection after organ transplantation, has previously been shown to enhance the potency of gefitinib. Hangxiang Wang and colleagues at Zhejiang University, Hangzhou, China, have successfully combined cyclosporin A and gefitinib, two poorly water-soluble and slowly absorbed drugs, into stable injectable nanoparticles that delay the growth of gefitinib resistant human lung cancer cells as well as the growth of drug resistant tumors in mice. Importantly, this novel co-formulation was more effective than oral co-administration of the two drugs. Further investigation into this drug delivery route could yield much needed alternative treatments for patients with multidrug-resistant cancers.

Platinum(iv) prodrugs with long lipid chains for drug delivery and overcoming cisplatin resistance

Platinum(iv) prodrugs of clinically used cisplatin and oxaliplatin with two axial long lipid chains were developed for nanoparticle delivery to combat cisplatin resistance.

H2O2-Responsive Nanoparticle Based on the Supramolecular Self-Assemble of Cyclodextrin

Designing stimuli responsive, controllable and biocompatible multifunctional nanoparticles is an important progress in the current quest for drug delivery systems. Herein, we devoted to developing a β-cyclodextrin (β-CD) based drug delivery nanoparticles (NPs) that release Bovine serum albumin (BSA) via glucose-responsive gate. The design involves synthesis of sodium alginate with β-CD modified (Alg-β-CD) and methoxypolyethylene glycol (mPEG-Fc) containing ferrocene (Fc) uncharged end-capping. When α-cyclodextrin (α-CD) was added with these two segments, the stable non-covalent supramolecular structure of Alg-β-CD/mPEG-Fc/α-CD can be self-assembled into NPs in aqueous solution. BSA loaded Alg-β-CD/mPEG-Fc/α-CD also has been prepared. Interestingly, these supramolecular Alg-β-CD/mPEG-Fc/α-CD/BSA NPs showed uniform sphere structure and constant BSA loading content. Also, this new kind of NPs can disassemble in the present of hydrogen peroxide (H2O2). Since glucose oxidase (GOD) can oxidize glucose and produce H2O2, so this kind of polymeric NPs can also have glucose responsive behavior in the GOD containing environment. Developed functional Alg-β-CD/mPEG-Fc/α-CD might be a promising drug delivery strategy for diabetes or immunotherapy with more efficiency.

Perfluorooctylbromide nanoparticles for ultrasound imaging and drug delivery

Perfluorooctylbromide nanoparticles (PFOB NPs) are a type of multifunctional nanotechnology that has been studied for various medical applications. Commercial ultrasound contrast agents (UCAs) suffer from the following limitations: short half-lives in vivo, high background signal and restricted distribution in the vascular circulation due to their micrometer dimensions. PFOB NPs are new potential UCAs that persist for long periods in the circulatory system, possess a relatively stable echogenic response without increasing the background signal and exhibit lower acoustic attenuation than commercial UCAs. Furthermore, PFOB NPs may also serve as drug delivery vehicles in which drugs are dissolved in the outer lipid or polymer layer for subsequent delivery to target sites in site-targeted therapy. The use of PFOB NPs as carriers has the potential advantage of selectively delivering payloads to the target site while improving visualization of the site using ultrasound (US) imaging. Unfortunately, the application of PFOB NPs to the field of ultrasonography has been limited because of the low intensity of US reflection. Numerous researchers have realized the potential use of PFOB NPs as UCAs and thus have developed alternative approaches to apply PFOB NPs in ultrasonography. In this article, we review the latest approaches for using PFOB NPs to enhance US imaging in vivo. In addition, this article emphasizes the application of PFOB NPs as promising drug delivery carriers for cancer and atherosclerosis treatments, as PFOB NPs can transport different drug payloads for various applications with good efficacy. We also note the challenges and future study directions for the application of PFOB NPs as both a delivery system for therapeutic agents and a diagnostic agent for ultrasonography.

Reprogramming axial ligands facilitates the self-assembly of a platinum(iv) prodrug: overcoming drug resistance and safer in vivo delivery of cisplatin

We herein reprogrammed axial ligands of platinum(iv) prodrugs, conferring the constructed prodrug entities with the ability to self-assemble in aqueous solution.

Improving the carrier stability and drug loading of unimolecular micelle-based nanotherapeutics for acid-activated drug delivery and enhanced antitumor therapy

Nanomedicines based on unimolecular micelles (UMs) have shown unique advantages such as high micellar stability, programmed cargo delivery and enhanced therapeutic efficiency.

Highly functionalized pyrrolidine analogues: stereoselective synthesis and caspase-dependent apoptotic activity

Spiropyrrolidines were synthesized employing a new class of azomethine ylide for the first time and were tested for their anticancer activity, where the cell death mechanism revealed that it is occurring through the caspase-3 dependent pathway.