Molecular Self-Assembly of Bile Acid-Phospholipids Controls the Delivery of Doxorubicin and Mice Survivability

Engineering Novel Amphiphilic Platinum(IV) Complexes to Co-Deliver Cisplatin and Doxorubicin

In this study, we report a novel platinum-doxorubicin conjugate that demonstrates superior therapeutic indices to cisplatin, doxorubicin, or their combination, which are commonly used in cancer treatment. This new molecular structure (1) was formed by conjugating an amphiphilic Pt(IV) prodrug of cisplatin with doxorubicin. Due to its amphiphilic nature, the Pt(IV)-doxorubicin conjugate effectively penetrates cell membranes, delivering both cisplatin and doxorubicin payloads intracellularly. The intracellular accumulation of these payloads was assessed using graphite furnace atomic absorption spectrometry and fluorescence imaging. Since the therapeutic effects of cisplatin and doxorubicin stem from their ability to target nuclear DNA, we hypothesized that the amphiphilic Pt(IV)-doxorubicin conjugate (1) would effectively induce nuclear DNA damage toward killing cancer cells. To test this hypothesis, we used flow the cytometric analysis of phosphorylated H2AX (γH2AX), a biomarker of nuclear DNA damage. The Pt(IV)-doxorubicin conjugate (1) markedly induced γH2AX in treated MDA-MB-231 breast cancer cells, showing higher levels than cells treated with either cisplatin or doxorubicin alone. Furthermore, MTT cell viability assays revealed that the enhanced DNA-damaging capability of complex 1 resulted in superior cytotoxicity and selectivity against human cancer cells compared to cisplatin, doxorubicin, or their combination. Overall, the development of this amphiphilic Pt(IV)-doxorubicin conjugate represents a new form of combination therapy with improved therapeutic efficacy.

Antibody-decorated chitosan-iodoacetamide-coated nanocarriers for the potential delivery of doxorubicin to breast cancer cells

Using an active targeting approach of chemotherapeutics-loaded nanocarriers (NCs) with monoclonal antibodies is a potential strategy to improve the specificity of the delivery systems and reduce adverse reactions of chemotherapeutic drugs. Specific targeting of the human epidermal growth factor receptor-2 (HER-2), expressed excessively in HER-2-positive breast cancer cells, can be achieved by conjugating NCs with an anti-HER-2 monoclonal antibody. We constructed trastuzumab-conjugated chitosan iodoacetamide-coated NCs containing doxorubicin (Tras-Dox-CHI-IA-NCs) as a tumor-targeted drug delivery system, during the study. Chitosan-iodoacetamide (CHI-IA) was synthesized and utilized to prepare trastuzumab-conjugated NCs (Tras-NCs). The morphology, physicochemical properties, drug loading, drug release, and biological activities of the NCs were elucidated. The Tras-NCs were spherical, with a particle size of approximately 76 nm, and had a positive zeta potential; after incorporating the drug, the size of the Tras-NC increased. A prolonged, 24-h drug release from the NCs was achieved. The Tras-NCs exhibited high cellular accumulation and significantly higher antitumor activity against HER-2-positive breast cancer cells than the unconjugated NCs and the drug solution. Therefore, Tras-Dox-CHI-IA-NCs could be a promising nanocarrier for HER-2-positive breast cancer.

Albumin Nanoparticles Surface Decorated with a Tumor-Homing Peptide Help in Selective Killing of Triple-Negative Breast Cancer Cells

In this article, we describe a method of delivery of doxorubicin using a novel tumor-homing peptide-based albumin nanoparticle system to triple-negative breast cancer cells (TNBC). The absence and reduced expression of the hormone (estrogen, progesterone) and HER2 (human epidermal growth factor 2) receptors, respectively, render TNBC patients nonsusceptible to different available targeted therapies. These peptide-modified nanoparticles could be taken up by TNBC cells more effectively than their bare counterparts. The drug-loaded peptide-modified nanoparticles achieved an optimal but crucial balance between cell killing in cancerous cells and cell survival in the noncancerous ones. This appears to be because of different routes of entry and subsequent fate of the bare and peptide-modified nanoparticles in cancerous and noncancerous cells. In a TNBC mouse model, the peptide-modified system fared better than the free drug in mounting an antitumor response while not being toxic systemically.

Self-assembled supramolecular nanomicelles from a bile acid-docetaxel conjugate are highly tolerable with improved therapeutic efficacy

Herein, we present the engineering of a supramolecular nanomicellar system that is composed of self-assembled units of the PEGylated lithocholic acid (LCA)-docetaxel (DTX) conjugate (LCA-DTX-PEG). We tethered a short polyethylene glycol unit to LCA and used an esterase-sensitive ester linkage between DTX and LCA. The LCA-DTX-PEG conjugate formed nanomicelles (LCA-DTX-PEG NMs) with ∼160 nm hydrodynamic diameter that are sensitive to cellular esterases and maximized the release of DTX under high esterase exposure. LCA-DTX-PEG NMs were found to be effective as the parent drug in breast cancer cells by stabilizing tubulin and arresting the cells in the G₂/M phase. We determined the maximum tolerated dose (MTD) and systemic and vital organ toxicity of LCA-DTX-PEG NMs in mice, rats, and rabbits. LCA-DTX-PEG NMs showed a MTD of >160 mg kg^-1 and are found to be safe in comparison with their parent FDA-approved drug formulation (Taxotere® or DTX-TS) that is highly toxic. LCA-DTX-PEG NMs effectively reduced the tumor volume and increased the survival of 4T1 tumor-bearing mice with improved blood circulation time of the drug and its higher accumulation in tumor tissues. Therefore, this study highlights the potential of PEGylated bile acid-drug conjugate based nanomicelles for the development of next generation cancer therapeutics.

Cellular viability and osteogenic differentiation potential of human gingiva-derived stem cells in 2D culture following treatment with anionic, cationic, and neutral liposomes containing doxorubicin

The effects of doxorubicin, particularly doxorubicin liposome, on stem cells have remained to be fully elucidated. The aim of the present study was to evaluate the effects of anionic, cationic and neutral liposomes loaded with doxorubicin on the viability and osteogenic differentiation potential of human gingiva-derived stem cells in two-dimensional culture. Doxorubicin-loaded liposomes were prepared using the traditional thin-lipid-film hydration method. Stem cells were seeded on a culture plate and maintained in osteogenic media. The morphology of the stem cells was observed under an inverted microscope. The number of viable cells was determined using a Cell-Counting Kit-8 assay. The alkaline phosphatase activity was assessed and Alizarin Red S staining was performed to evaluate osteogenic differentiation. A higher concentration of doxorubicin caused noticeable changes in the morphology of the stem cells. Decreases in cellular viability were observed after applying doxorubicin. The application of doxorubicin, particularly at higher concentrations, produced a noticeable decrease in alkaline phosphatase activity and Alizarin Red S staining. The present study indicated that application of doxorubicin with or without liposomes reduced the cellular viability and osteogenic differentiation. Among the different treatments, the doxorubicin-loaded cationic liposomes induced the strongest reduction in the cellular viability and osteogenic differentiation in the stem cell culture.

A New Way to Promote Molecular Drug Release during Medical Treatment: A Polyelectrolyte Matrix on a Piezoelectric-Dielectric Energy Conversion Substrate

Enhanced drug releases in a timely manner during urgent medical treatments would significantly enhance the prognosis of patients. Inspired by the facilitated molecular transports by the potentials, an enhanced drug release strategy driven by mechanical disturbances that widely exist in medical treatment processes is proposed. This strategy is enabled by a functional material comprised of multilayers of dendrimers as the drug reservoir, which are built on a piezoelectric-dielectric flexible film with reduced graphene oxide fillers. The generated voltages are higher and last longer than that in regular piezoelectric films. Photochemical crosslinking leads to a stable drug matrix which is even sustained in electric fields and high ionic strengths. The device enhances releases of positively, negatively, and zwitterionically charged molecules in response to mechanical stimuli and supports high cell viabilities. An illustrative application is demonstrated by preparing the material on the surface of a gastric lavage tube. The results show that the release of antiemetic drug increased by 200% within 60 min in response to forces mimicking human swallowing. This study contributes an integrative material that can realize electrically triggered releases that are previously only realized using complicated electrochemical setups. It is believed that this material can facilitate medicine applications in various emergent situations.