Beyond Formulation: Contributions of Nanotechnology for Translation of Anticancer Natural Products into New Drugs

Old drug, new tricks: polymer-based nanoscale systems for effective cytarabine delivery

Cytarabine, an antimetabolite antineoplastic agent, has been utilized to treat various cancers. However, because of its short half-life, low stability, and limited bioavailability, achieving an optimal plasma concentration requires continuous intravenous administration, which can lead to toxicity in normal cells and tissues. Addressing these limitations is crucial to optimize the therapeutic efficacy of cytarabine while minimizing its adverse effects. The use of novel drug delivery systems, such as polymer-based nanocarriers have emerged as promising vehicles for targeted drug delivery due to their unique properties, including high stability, biocompatibility, and tunable release kinetics. In this review, we examine the application of various polymer-based nanocarriers, including polymeric nanoparticles, polymeric micelles, dendrimers, polymer-drug conjugates, and nano-hydrogels, for the delivery of cytarabine. The article highlights the limitations of conventional cytarabine administration which often lead to suboptimal therapeutic outcomes and systemic toxicity. The rationale for using polymer-based nanocarriers is discussed, highlighting their ability to overcome challenges by providing controlled drug release, improved stability, and enhanced targeting capabilities. In summary, this review offers a valuable resource for drug delivery scientists by providing insights into the design principles, formulation strategies, and potential applications of polymer-based nanocarriers that can enhance the therapeutic efficacy of cytarabine.

Therapeutic Applications of Nanomedicine: Recent Developments and Future Perspectives

The concept of nanomedicine has evolved significantly in recent decades, leveraging the unique phenomenon known as the enhanced permeability and retention (EPR) effect. This has facilitated major advancements in targeted drug delivery, imaging, and individualized therapy through the integration of nanotechnology principles into medicine. Numerous nanomedicines have been developed and applied for disease treatment, with a particular focus on cancer therapy. Recently, nanomedicine has been utilized in various advanced fields, including diagnosis, vaccines, immunotherapy, gene delivery, and tissue engineering. Multifunctional nanomedicines facilitate concurrent medication delivery, therapeutic monitoring, and imaging, allowing for immediate responses and personalized treatment plans. This review concerns the major advancement of nanomaterials and their potential applications in the biological and medical fields. Along with this, we also mention the various clinical translations of nanomedicine and the major challenges that nanomedicine is currently facing to overcome the clinical translation barrier.

Exploring contemporary breakthroughs in utilizing vesicular nanocarriers for breast cancer therapy

Breast cancer (BC) is a heterogeneous disease with various morphological features, clinicopathological conditions and responses to different therapeutic options, which is responsible for high mortality and morbidity in women. The heterogeneity of BC necessitates new strategies for diagnosis and treatment, which is possible only by cautious harmonization of the advanced nanomaterials. Recent developments in vesicular nanocarrier therapy indicate a paradigm shift in breast cancer treatment by providing an integrated approach to address current issues. This review provides a detailed classification of various nanovesicles in the treatment of BC with a special emphasis on recent advances, challenges in translating nanomaterials and future potentials.

The therapeutic potential of natural metabolites in targeting endocrine-independent HER-2-negative breast cancer

Breast cancer (BC) is a heterogenous disease, with prognosis and treatment options depending on Estrogen, Progesterone receptor, and Human Epidermal Growth Factor Receptor-2 (HER-2) status. HER-2 negative, endocrine-independent BC presents a significant clinical challenge with limited treatment options. To date, promising strategies like immune checkpoint inhibitors have not yielded breakthroughs in patient prognosis. Despite being considered archaic, agents derived from natural sources, mainly plants, remain backbone of current treatment. In this context, we critically analyze novel naturally-derived drug candidates, elucidate their intricate mechanisms of action, and evaluate their pre-clinical in vitro and in vivo activity in endocrine-independent HER-2 negative BC. Since pre-clinical research success often does not directly correlate with drug approval, we focus on ongoing clinical trials to uncover current trends. Finally, we demonstrate the potential of combining cutting-edge technologies, such as antibody-drug conjugates or nanomedicine, with naturally-derived agents, offering new opportunities that utilize both traditional cytotoxic agents and new metabolites.

Polymersomes as the Next Attractive Generation of Drug Delivery Systems: Definition, Synthesis and Applications

Polymersomes are artificial nanoparticles formed by the self-assembly process of amphiphilic block copolymers composed of hydrophobic and hydrophilic blocks. They can encapsulate hydrophilic molecules in the aqueous core and hydrophobic molecules within the membrane. The composition of block copolymers can be tuned, enabling control of characteristics and properties of formed polymersomes and, thus, their application in areas such as drug delivery, diagnostics, or bioimaging. The preparation methods of polymersomes can also impact their characteristics and the preservation of the encapsulated drugs. Many methods have been described, including direct hydration, thin film hydration, electroporation, the pH-switch method, solvent shift method, single and double emulsion method, flash nanoprecipitation, and microfluidic synthesis. Considering polymersome structure and composition, there are several types of polymersomes including theranostic polymersomes, polymersomes decorated with targeting ligands for selective delivery, stimuli-responsive polymersomes, or porous polymersomes with multiple promising applications. Due to the shortcomings related to the stability, efficacy, and safety of some therapeutics in the human body, polymersomes as drug delivery systems have been good candidates to improve the quality of therapies against a wide range of diseases, including cancer. Chemotherapy and immunotherapy can be improved by using polymersomes to deliver the drugs, protecting and directing them to the exact site of action. Moreover, this approach is also promising for targeted delivery of biologics since they represent a class of drugs with poor stability and high susceptibility to in vivo clearance. However, the lack of a well-defined regulatory plan for polymersome formulations has hampered their follow-up to clinical trials and subsequent market entry.

Smart Poly(lactide)-b-poly(triethylene glycol methyl ether methacrylate) (PLA-b-PTEGMA) Block Copolymers: One-Pot Synthesis, Temperature Behavior, and Controlled Release of Paclitaxel

This paper introduces a new class of amphiphilic block copolymers created by combining two polymers: polylactic acid (PLA), a biocompatible and biodegradable hydrophobic polyester used for cargo encapsulation, and a hydrophilic polymer composed of oligo ethylene glycol chains (triethylene glycol methyl ether methacrylate, TEGMA), which provides stability and repellent properties with added thermo-responsiveness. The PLA-b-PTEGMA block copolymers were synthesized using ring-opening polymerization (ROP) and reversible addition-fragmentation chain transfer (RAFT) polymerization (ROP-RAFT), resulting in varying ratios between the hydrophobic and hydrophilic blocks. Standard techniques, such as size exclusion chromatography (SEC) and ¹H NMR spectroscopy, were used to characterize the block copolymers, while ¹H NMR spectroscopy, 2D nuclear Overhauser effect spectroscopy (NOESY), and dynamic light scattering (DLS) were used to analyze the effect of the hydrophobic PLA block on the LCST of the PTEGMA block in aqueous solutions. The results show that the LCST values for the block copolymers decreased with increasing PLA content in the copolymer. The selected block copolymer presented LCST transitions at physiologically relevant temperatures, making it suitable for manufacturing nanoparticles (NPs) and drug encapsulation-release of the chemotherapeutic paclitaxel (PTX) via temperature-triggered drug release mechanism. The drug release profile was found to be temperature-dependent, with PTX release being sustained at all tested conditions, but substantially accelerated at 37 and 40 °C compared to 25 °C. The NPs were stable under simulated physiological conditions. These findings demonstrate that the addition of hydrophobic monomers, such as PLA, can tune the LCST temperatures of thermo-responsive polymers, and that PLA-b-PTEGMA copolymers have great potential for use in drug and gene delivery systems via temperature-triggered drug release mechanisms in biomedicine applications.

Synchronized delivery of dual-drugs for potentiating combination chemotherapy based on smart triple-responsive polymeric micelles

Here, we combined reversible addition-fragmentation chain transfer (RAFT) polymerization and amide coupling reaction to develop a novel drug-polymer conjugate using poly(AMA-co-IMMA)-b-poly(OEGMA) (termed as PAIPO) as nanocarriers. In order to enhance cellular uptake and obtain subsequent endo/lysosomal escape capacity, the dual-drugs-conjugated prodrug was then coupled with 2,3-dimethylmaleimide (DA) moieties and implanted with imidazolyl groups, respectively. Paclitaxel (PTX) was conjugated to PAIPO via 3,3'-dithiodipropionic acid (DPA) to construct a GSH-responsive moiety, while doxorubicin (DOX) was conjugated to PAIPO via 4-formyl benzoic acid to construct a pH-responsive moiety, which synergistically enabled a synchronized and precise drug delivery. The micelles self-assembled from DOX/PTX@PAIPO^DA showed an ideal average diameter (163.2-178.3 nm), contributing to passive targeting by the EPR effect. Moreover, a switch of the surface Zeta potential of micelles from steady negatively charged (- 9.74 ± 0.54 mV) at pH 7.4 to positively charged (+ 6.33 ± 1.25 mV) at pH 6.5, facilitated the long blood circulation and cellular endocytosis of micelles, respectively. More importantly, in vitro studies confirmed that ^DAM(DOX_n/PTX) exhibited a strong synergism against tumor cells, and under slightly acidic conditions (pH 6.5), the combination index (CI) values for ^DAM(DOX₁/PTX) on HeLa and Skov-3 cells were estimated to be 0.47 and 0.49 (previous to be 0.50 and 0.56 at pH 7.4), respectively. And in vivo results showed effective tumor accumulation potential, remarkable biosafety, and biocompatibility. Combined, such synchronized delivery approach based on multi-responsive micelles might potentiate the efficacy of combination chemotherapy in clinical cancer treatment.

Contributions of nanotechnology to the intraductal drug delivery for local treatment and prevention of breast cancer

Breast cancer is a major public health problem, affecting millions of people. It is a very heterogeneous disease, with localized and invasive forms, and treatment generally consists of a combination of surgery and radiotherapy followed by administration of estrogen receptor modulators or aromatase inhibitors. Given its heterogeneity, management strategies that take into consideration the type of disease and biological markers and can provide more personalized and local treatment are required. More recently, the intraductal administration (i.e., into the breast ducts) of drugs has attracted significant attention due to its ability of providing drug distribution through the ductal tree in a minimally invasive manner. Although promising, intraductal administration is not trivial, and difficulties in duct identification and cannulation are important challenges to the further development of this route. New drug delivery strategies such as nanostructured systems can help to achieve the full benefits of the route due to the possibility of prolonging tissue retention, improving targeting and selectivity, increasing cytotoxicity and reducing the frequency of administration. This review aims at discussing the potential benefits and challenges of intraductal administration, focusing on the design and use of nanocarriers as innovative and feasible strategies for local breast cancer therapy and prevention.

Updates on the anticancer potential of garlic organosulfur compounds and their nanoformulations: Plant therapeutics in cancer management

Garlic (Allium sativum L.) possesses numerous pharmacological potential, including antibacterial, antiarthritic, antithrombotic, anticancer, hypoglycemic, and hypolipidemic effects. The anti-cancer action of garlic is likely the best researched of the many advantageous pharmacological effects, and its use offers significant protection against the risk of developing cancer. A few active metabolites of garlic have been reported to be essential in the destruction of malignant cells due to their multi-targeted activities and lack of significant toxicity. The bioactive compounds in garlic having anticancer properties include diallyl trisulfide, allicin, allyl mercaptan diallyl disulfide, and diallyl sulphide. Different garlic-derived constituents and their nanoformulations have been tested for their effects against various cancers including skin, ovarian, prostate, gastric, breast, and lung, colorectal, liver, oral, and pancreatic cancer. The objective of this review is to summarize the antitumor activity and associated mechanisms of the organosulfur compounds of garlic in breast carcinoma. Breast cancer continues to have a significant impact on the total number of cancer deaths worldwide. Global measures are required to reduce its growing burden, particularly in developing nations where incidence is increasing quickly and fatality rates are still high. It has been demonstrated that garlic extract, its bioactive compounds, and their use in nanoformulations can prevent breast cancer in all of its stages, including initiation, promotion, and progression. Additionally, these bioactive compounds affect cell signaling for cell cycle arrest and survival along with lipid peroxidation, nitric oxide synthase activity, epidermal growth factor receptor, nuclear factor kappa B (NF-κB), and protein kinase C in breast carcinoma. Hence, this review deciphers the anticancer potential of garlic components and its nanoformulations against several breast cancer thereby projecting it as a potent drug candidate for efficient breast cancer management.

Doxorubicin-An Agent with Multiple Mechanisms of Anticancer Activity

Doxorubicin (DOX) constitutes the major constituent of anti-cancer treatment regimens currently in clinical use. However, the precise mechanisms of DOX's action are not fully understood. Emerging evidence points to the pleiotropic anticancer activity of DOX, including its contribution to DNA damage, reactive oxygen species (ROS) production, apoptosis, senescence, autophagy, ferroptosis, and pyroptosis induction, as well as its immunomodulatory role. This review aims to collect information on the anticancer mechanisms of DOX as well as its influence on anti-tumor immune response, providing a rationale behind the importance of DOX in modern cancer therapy.

Advances in nanomaterial-based targeted drug delivery systems

Nanomaterial-based drug delivery systems (NBDDS) are widely used to improve the safety and therapeutic efficacy of encapsulated drugs due to their unique physicochemical and biological properties. By combining therapeutic drugs with nanoparticles using rational targeting pathways, nano-targeted delivery systems were created to overcome the main drawbacks of conventional drug treatment, including insufficient stability and solubility, lack of transmembrane transport, short circulation time, and undesirable toxic effects. Herein, we reviewed the recent developments in different targeting design strategies and therapeutic approaches employing various nanomaterial-based systems. We also discussed the challenges and perspectives of smart systems in precisely targeting different intravascular and extravascular diseases.

Effect of Nanoparticles of DOX and miR-125b on DNA Damage Repair in Glioma U251 Cells and Underlying Mechanisms

Glioma is the most common primary craniocerebral malignant tumor, arising from the canceration of glial cells in the brain and spinal cord. The quality of life and prognosis of patients with this disease are still poor. Doxorubicin (DOX) is one of the most traditional and economical chemotherapeutic drugs for the treatment of glioma, but its toxic effect on normal cells and the resistance of tumor cells to DOX make the application of DOX in the treatment of glioma gradually less effective. To solve this problem, we co-encapsulated DOX and endogenous tumor suppressor miR-125b into nanoparticles (NPs) by nanoprecipitation methods, and passively targeted them into glioma cells. In vitro experiments show that miR-125b and DOX can be effectively encapsulated into nanoparticles with different ratios, and by targeting YES proto-oncogene 1 (YES1), they can affect the adenosine 5′-monophosphate (AMP)-activated protein kinase (AMPK)/p53 pathway and induce brain glioma cell apoptosis. They can also affect the DNA damage repair process and inhibit cell proliferation. The obtained data suggest that co-delivery of DOX and miR-125b could achieve synergistic effects on tumor suppression. Nanosystem-based co-delivery of tumor suppressive miRNAs and chemotherapeutic agents may be a promising combined therapeutic strategy for enhanced anti-tumor therapy.