Polydopamine-Decorated Orlistat-Loaded Hollow Capsules with an Enhanced Cytotoxicity against Cancer Cell Lines

Exploring the metabolic alterations in cervical cancer induced by HPV oncoproteins: From mechanisms to therapeutic targets

The role of human Papillomavirus (HPV) in metabolic reprogramming is implicated in the development and progression of cervical cancer. During carcinogenesis, cancer cells modify various metabolic pathways to generate energy and sustain their growth and development. Cervical cancer, one of the most prevalent malignancies affecting women globally, involves metabolic alterations such as increased glycolysis, elevated lactate production, and lipid accumulation. The oncoproteins, primarily E6 and E7, which are encoded by high-risk HPVs, facilitate the accumulation of several cancer markers, promoting not only the growth and development of cancer but also metastasis, immune evasion, and therapy resistance. HPV oncoproteins interact with cellular MYC (c-MYC), retinoblastoma protein (pRB), p53, and hypoxia-inducible factor 1α (HIF-1α), leading to the induction of metabolic reprogramming and favour the Warburg effect. Metabolic reprogramming enables HPV to persist for an extended period and accelerates the progression of cervical cancer. This review summarizes the role of HPV oncoproteins in metabolic reprogramming and their contributions to the development and progression of cervical cancer. Additionally, this review provides insights into how metabolic reprogramming opens avenues for novel therapeutic strategies, including the discovery of new and repurposed drugs that could be applied to treat cervical cancer.

Potential Protective Effect of Orlistat: A Formulation of Nanocrystals Targeting Inflammation, Oxidative Stress, and Apoptosis in an Experimental Model of Doxorubicin-Induced Cardiotoxicity

Background: Doxorubicin (DOX) is a widely used chemotherapeutic agent; nevertheless, cardiotoxicity limits its effectiveness. Orlistat (Orli) is an irreversible lipase enzyme inhibitor with poor solubility and bioavailability. Furthermore, Orli has a favorable impact on the decrease in cardiometabolic risk variables. Thus, this study aimed to investigate the novel use of Orlistat Nanocrystals (Orli-Nanocrystals) to mitigate DOX-induced cardiotoxicity and to identify probable pathways behind the cardioprotective effects. Methods: The pharmacokinetic parameters-area under % dose/g heart time curve (AUC0→4h), Drug targeting index (DTI), and relative targeting efficiency (RTE)-were calculated. Furthermore, experimental design mice were categorized into six groups: a (1) Normal control group, (2) Orli-Free group, (3) Orli-Nanocrystals group, (4) DOX group, (5) Orli-Free-DOX group, and (6) Orli-Nanocrystals-DOX group. All treatments were intraperitoneally injected once daily for 14 days with a single dose of DOX (15 mg/kg) on the 12th day for 4, 5, and 6 groups. Results: The pharmacokinetic parameters (Cmax, AUC) following oral administration of Orli-Nanocrystals presented a significant difference (higher values) in comparison to Orli due to the enhanced extent of the absorption of nanocrystals and, subsequently, their distribution to the heart. The study results indicated that DOX caused significant cardiotoxicity, as revealed by a remarkable rise in cardiac function biomarkers like LDH and CK-MB, which involve enzyme activities. Additionally, cardiac MDA content also increased; however, glutathione peroxidase, catalase, and superoxide dismutase activities were decreased. In the same context, DOX was found to have a remarkable downregulation in Nrf2, HO-1, Sirt-1, and Bcl2, while the upregulation of NF-κB, TNF-α, and BAX gene and protein expression occurred. Pretreatment with Orli-Nanocrystals displayed the most notable recovery of the altered immunohistochemical, histological, and biochemical characteristics as compared to the Orli-Free group. Conclusions: This work is the first investigation into the potential use of antioxidant, anti-inflammatory, and anti-apoptotic characteristics of Orli-Nanocrystals to protect against DOX-induced cardiotoxicity in vivo.

Precious Cargo: The Role of Polymeric Nanoparticles in the Delivery of Covalent Drugs

Covalent drugs can offer significant advantages over non-covalent drugs in terms of pharmacodynamics (i.e., target-binding properties). However, the development of covalent drugs is sometimes hampered by pharmacokinetic limitations (e.g., low bioavailability, rapid metabolism and toxicity due to off-target binding). Polymeric nanoparticles offer a potential solution to these limitations. Delivering covalent drugs via polymeric nanoparticles provides myriad benefits in terms of drug solubility, permeability, lifetime, selectivity, controlled release and the opportunity for synergistic administration alongside other drugs. In this short review, we examine each of these benefits in turn, illustrated through multiple case studies.

Precision targeting in hepatocellular carcinoma: Exploring ligand-receptor mediated nanotherapy

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and poses a major challenge to global health due to its high morbidity and mortality. Conventional chemotherapy is usually targeted to patients with intermediate to advanced stages, but it is often ineffective and suffers from problems such as multidrug resistance, rapid drug clearance, nonspecific targeting, high side effects, and low drug accumulation in tumor cells. In response to these limitations, recent advances in nanoparticle-mediated targeted drug delivery technologies have emerged as breakthrough approaches for the treatment of HCC. This review focuses on recent advances in nanoparticle-based targeted drug delivery systems, with special attention to various receptors overexpressed on HCC cells. These receptors are key to enhancing the specificity and efficacy of nanoparticle delivery and represent a new paradigm for actively targeting and combating HCC. We comprehensively summarize the current understanding of these receptors, their role in nanoparticle targeting, and the impact of such targeted therapies on HCC. By gaining a deeper understanding of the receptor-mediated mechanisms of these innovative therapies, more effective and precise treatment of HCC can be achieved.

Polydopamine Nanomaterials for Overcoming Current Challenges in Cancer Treatment

In efforts to overcome current challenges in cancer treatment, multifunctional nanoparticles are attracting growing interest, including nanoparticles made with polydopamine (PDA). PDA is a nature-inspired polymer with a dark brown color. It has excellent biocompatibility and is biodegradable, offering a range of extraordinary inherent advantages. These include excellent drug loading capability, photothermal conversion efficiency, and adhesive properties. Though the mechanism of dopamine polymerization remains unclear, PDA has demonstrated exceptional flexibility in engineering desired morphology and size, easy and straightforward functionalization, etc. Moreover, it offers enormous potential for designing multifunctional nanomaterials for innovative approaches in cancer treatment. The aim of this work is to review studies on PDA, where the potential to develop multifunctional nanomaterials with applications in photothermal therapy has been demonstrated. Future prospects of PDA for developing applications in enhancing radiotherapy and/or immunotherapy, including for image-guided drug delivery to boost therapeutic efficacy and minimal side effects, are presented.

Fatty acid metabolism: A new therapeutic target for cervical cancer

Cervical cancer (CC) is one of the most common malignancies in women. Cancer cells can use metabolic reprogramming to produce macromolecules and ATP needed to sustain cell growth, division and survival. Recent evidence suggests that fatty acid metabolism and its related lipid metabolic pathways are closely related to the malignant progression of CC. In particular, it involves the synthesis, uptake, activation, oxidation, and transport of fatty acids. Similarly, more and more attention has been paid to the effects of intracellular lipolysis, transcriptional regulatory factors, other lipid metabolic pathways and diet on CC. This study reviews the latest evidence of the link between fatty acid metabolism and CC; it not only reveals its core mechanism but also discusses promising targeted drugs for fatty acid metabolism. This study on the complex relationship between carcinogenic signals and fatty acid metabolism suggests that fatty acid metabolism will become a new therapeutic target in CC.

Anticancer Activity of Nano-formulated Orlistat-Dopamine Conjugates Through Self-Assembly

Orlistat, an FDA-approved fatty acid inhibitor for obesity treatment, demonstrates certain low and greatly varied anticancer abilities. In a previous study, we revealed a synergistic effect between orlistat and dopamine in cancer treatment. Here, orlistat-dopamine conjugates (ODCs) with defined chemical structures were synthesized. The ODC by design underwent polymerization and self-assembly in the presence of oxygen to form nano-sized particles (Nano-ODCs) spontaneously. The resulted Nano-ODCs of partial crystalline structures demonstrated good water dispersion to form stable Nano-ODC suspensions. Because of the bioadhesive property of the catechol moieties, once administered, Nano-ODCs were quickly accumulated on cell surfaces and efficiently uptaken by cancer cells. In the cytoplasm, Nano-ODC experienced biphasic dissolution followed by spontaneous hydrolysis to release intact orlistat and dopamine. Besides elevated levels of intracellular reactive oxygen species (ROS), the co-localized dopamine also induced mitochondrial dysfunctions through monoamine oxidases (MAOs)-catalyzed dopamine oxidation. The strong synergistic effects between orlistat and dopamine determined a good cytotoxicity activity and a unique cell lysis mechanism, explaining the distinguished activity of Nano-ODC to drug-sensitive and -resistant cancer cells. This new technology-enabled orlistat repurposing will contribute to overcoming drug resistance and the improvement of cancer chemotherapy.

Tunable Properties of Polydopamine Nanoparticles and Coated Surfaces

Polydopamine (PDA) nanoparticles and PDA-coated surfaces have wide applications due to PDA's unique reactivity and efficient coating ability on nearly any surface. However, challenges in manipulating and controlling dopamine polymerization and thus the PDA nanoparticle formations and surface coatings still exist. Here, dopamine with a tetraborate (borax)-protected catechol group was utilized to tune the properties of PDA nanoparticles and PDA coatings. This method allows us to (1) synthesize PDA nanoparticles with a narrow size distribution and low aggregation and (2) create surface coating with the desired PDA layer thickness and varying water contact angles. PDA nanoparticles and PDA-coated surfaces of varying but tunable chemical and physical properties will find wide applications. For example, such PDA-coated surfaces were successfully used to construct Ag nanoparticle patterned surfaces with varying Ag particle sizes and densities.

Knockdown of PGM1 enhances anticancer effects of orlistat in gastric cancer under glucose deprivation

Background

Phosphoglucomutase 1 (PGM1) acts as an important regulator in glucose metabolism. However, the role of PGM1 in gastric cancer (GC) remains unclear. This study aims to investigate the role of PGM1 and develop novel regimens based on metabolic reprogramming in GC.

Methods

Correlation and enrichment analyses of PGM1 were conducted based on The Cancer Genome Atlas database. Data derived from the Kaplan–Meier Plotter database were analyzed to evaluate correlations between PGM1 expression and survival time of GC patients. Cell counting kit-8, 5-Ethynyl-2-deoxyuridine, flow cytometry assays, generation of subcutaneous tumor and lung metastasis mouse models were used to determine growth and metastasis in vitro and in vivo. Cell glycolysis was detected by a battery of glycolytic indicators, including lactate, pyruvic acid, ATP production and glucose uptake. Fatty Acid Synthase (FASN) activity and expression levels of lipid enzymes were determined to reflect on lipid metabolism.

Results

Correlation and enrichment analyses suggested that PGM1 was closely associated with cell viability, proliferation and metabolism. PGM1 was overexpressed in GC tissues and cell lines. High PGM1 expression served as an indicator of shorter survival for specific subpopulation of GC patients. It was also correlated with pathological tumor stage and pathological tumor node metastasis stage of GC. Under the glucose deprivation condition, knockdown of PGM1 significantly suppressed cell viability, proliferation and glycolysis, whereas lipid metabolism was enhanced. Orlistat, as a drug that was designed to inhibit FASN activity, effectively induced apoptosis and suppressed lipid metabolism in GC. However, orlistat conversely increased glycolytic levels. Orlistat exhibited more significant inhibitive effects on GC progression after knockdown of PGM1 under glucose deprivation due to combination of glycolysis and lipid metabolism both in vitro and in vivo.

Conclusions

Downregulation of PGM1 expression under glucose deprivation enhanced anti-cancer effects of orlistat. This combination application may serve as a novel strategy for GC treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02193-3.

Biodegradable iron-coordinated hollow polydopamine nanospheres for dihydroartemisinin delivery and selectively enhanced therapy in tumor cells

As the semisynthetic derivative and active metabolite of the effective anti-malarial drug artemisinin, dihydroartemisinin (DHA) has been investigated as an emerging therapeutic agent for tumor treatment based on the cytotoxicity of free-radicals originating from interactions with ferrous ions. Meanwhile, simultaneously delivering DHA and iron ions to tumors for selectively killing cancer cells is still a great challenge in DHA tumor therapy. Herein, we develop a facile yet efficient strategy based on iron-coordinated hollow polydopamine nanospheres to load DHA (DHA@HPDA-Fe). The as-prepared nanoagent is biodegradable and exhibits controllable release of DHA and Fe ions in tumor microenvironments, resulting in ferrous ion-enhanced production of cytotoxic reactive oxygen species (ROS) by DHA and thus effectively killing the tumor cells. In vivo therapy experiments indicated that the anti-tumor efficacy of DHA@HPDA-Fe was about 3.05 times greater than that of free DHA, and the tumor inhibition ratio was 88.7% compared with the control group, accompanied by negligible side effects, indicating that the proposed nanomedicine platform is promising for anti-tumor applications.

Nanoparticles modified by polydopamine: Working as "drug" carriers

Inspired by the mechanism of mussel adhesion, polydopamine (PDA), a versatile polymer for surface modification has been discovered. Owing to its unique properties like extraordinary adhesiveness, excellent biocompatibility, mild synthesis requirements, as well as distinctive drug loading approach, strong photothermal conversion capacity and reactive oxygen species (ROS) scavenging facility, various PDA-modified nanoparticles have been desired as drug carriers. These nanoparticles with diverse nanostructures are exploited in multifunctions, consisting of targeting, imaging, chemical treatment (CT), photodynamic therapy (PDT), photothermal therapy (PTT), tissue regeneration ability, therefore have attracted great attentions in plenty biomedical applications. Herein, recent progress of PDA-modified nanoparticle drug carriers in cancer therapy, antibiosis, prevention of inflammation, theranostics, vaccine delivery and adjuvant, tissue repair and implant materials are reviewed, including preparation of PDA-modified nanoparticle drug carriers with various nanostructures and their drug loading strategies, basic roles of PDA surface modification, etc. The advantages of PDA modification in overcoming the existing limitations of cancer therapy, antibiosis, tissue repair and the developing trends in the future of PDA-modified nanoparticle drug carriers are also discussed.

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Multifunctional PDA-modified drug systems are introduced in terms of classification, synthesis and drug loading strategies.

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Basic roles of PDA surface modification in the drug systems are discussed.

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Biomedical applications and unique advantages of the PDA-modified nanoparticle working as drug carriers are illustrated.

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Challenges and perspectives for future development are proposed.

A glutathione-depleted prodrug platform of MnO2-coated hollow polydopamine nanospheres for effective cancer diagnosis and therapy

A biocompatible and efficient nanoplatform for tumor diagnosis and treatment was fabricated based on manganese oxide-coated hollow polydopamine loaded with dihydroartemisinin.