Nanotechnology-based Drug Delivery, Metabolism and Toxicity

Current advances in modulating tumor hypoxia for enhanced therapeutic efficacy

Hypoxia is a common feature of most solid tumors, which promotes the proliferation, invasion, metastasis, and therapeutic resistance of tumors. Researchers have been developing advanced strategies and nanoplatforms to modulate tumor hypoxia to enhance therapeutic effects. A timely review of this rapidly developing research topic is therefore highly desirable. For this purpose, this review first introduces the impact of hypoxia on tumor development and therapeutic resistance in detail. Current developments in the construction of various nanoplatforms to enhance tumor treatment in response to hypoxia are also systematically summarized, including hypoxia-overcoming, hypoxia-exploiting, and hypoxia-disregarding strategies. We provide a detailed discussion of the rationale and research progress of these strategies. Through a review of current trends, it is hoped that this comprehensive overview can provide new prospects for clinical application in tumor treatment. STATEMENT OF SIGNIFICANCE: As a common feature of most solid tumors, hypoxia significantly promotes tumor progression. Advanced nanoplatforms have been developed to modulate tumor hypoxia to enhanced therapeutic effects. In this review, we first introduce the impact of hypoxia on tumor progression. Current developments in the construction of various nanoplatforms to enhance tumor treatment in response to hypoxia are systematically summarized, including hypoxia-overcoming, hypoxia-exploiting, and hypoxia-disregarding strategies. We discuss the rationale and research progress of the above strategies in detail, and finally introduce future challenges for treatment of hypoxic tumors. By reviewing the current trends, this comprehensive overview can provide new prospects for clinical translatable tumor therapy.

Chitosan Nanoparticles Loaded with Quercetin and Valproic Acid: A Novel Approach for Enhancing Antioxidant Activity against Oxidative Stress in the SH-SY5Y Human Neuroblastoma Cell Line

BACKGROUND

Multiple drug-delivery systems obtained by loading nanoparticles (NPs) with different drugs that have different physicochemical properties present a promising strategy to achieve synergistic effects between drugs or overcome undesired effects. This study aims to develop a new NP by loading quercetin (Que) and valproic acid (VPA) into chitosan. In this context, our study investigated the antioxidant activities of chitosan NPs loaded with single and dual drugs containing Que against oxidative stress.

METHOD

The synthesis of chitosan NPs loaded with a single (Que or VPA) and dual drug (Que and VPA), the characterization of the NPs, the conducting of in vitro antioxidant activity studies, and the analysis of the cytotoxicity and antioxidant activity of the NPs in human neuroblastoma SH-SY5Y cell lines were performed.

RESULT

The NP applications that protected cell viability to the greatest extent against H2O2-induced cell damage were, in order, 96 µg/mL of Que-loaded chitosan NP (77.30%, 48 h), 2 µg/mL of VPA-loaded chitosan NP (70.06%, 24 h), 96 µg/mL of blank chitosan NP (68.31%, 48 h), and 2 µg/mL of Que- and VPA-loaded chitosan NP (66.03%, 24 h).

CONCLUSION

Our study establishes a successful paradigm for developing drug-loaded NPs with a uniform and homogeneous distribution of drugs into NPs. Chitosan NPs loaded with both single and dual drugs possessing antioxidant activity were successfully developed. The capability of chitosan NPs developed at the nanometer scale to sustain cell viability in SH-SY5Y cell lines implies the potential of intranasal administration of chitosan NPs for future studies, offering protective effects in central nervous system diseases.

Nanotechnological strategies to increase the oxygen content of the tumor

Hypoxia is a negative prognostic indicator of solid tumors, which not only changes the survival state of tumors and increases their invasiveness but also remarkably reduces the sensitivity of tumors to treatments such as radiotherapy, chemotherapy and photodynamic therapy. Thus, developing therapeutic strategies to alleviate tumor hypoxia has recently been considered an extremely valuable target in oncology. In this review, nanotechnological strategies to elevate oxygen levels in tumor therapy in recent years are summarized, including (I) improving the hypoxic tumor microenvironment, (II) oxygen delivery to hypoxic tumors, and (III) oxygen generation in hypoxic tumors. Finally, the challenges and prospects of these nanotechnological strategies for alleviating tumor hypoxia are presented.

Self-nanoemulsifying drug delivery systems (SNEDDS) of anti-cancer drugs: a multifaceted nanoplatform for the enhancement of oral bioavailability

OBJECTIVE

A significant problem faced by the health care industry today is that though there are numerous drugs available to tackle diseases like cancer, their intrinsic properties make it difficult to be delivered to patients in a feasible manner. One of the key players that have helped researchers overcome poor solubility and permeability of drugs is Nanotechnology, this article further iterates on the same.

SIGNIFICANCE

Nanotechnology is used as an umbrella term in pharmaceutics and describes under it multiple technologies. Upcoming nanotechnology is a Self Nanoemulsifying System which is considered to be a futuristic delivery system both due to its scientific simplicity and relative ease of patient delivery.

METHODS

Self-Nano Emulsifying Drug Delivery Systems (SNEDDS) are homogenous lipidic concoctions containing the drug solubilized in the oil phase and surfactants. The choice of components depends on the physicochemical properties of the drugs, the solubilization capability of oils and the physiological fate of the drug. The article contains further details of various methodologies that have been adopted by scientists to formulate and optimize such systems in order to make anticancer drugs orally deliverable.

RESULTS

The results that have been generated by scientists across the globe have been summarized in the article and all of the data supports the claim that SNEDDS significantly enhance the solubility and bioavailability of hydrophobic anticancer drugs.

CONCLUSIONS

This article mainly provides the application of SNEDDS in cancer therapy and concludes to provide a step for the oral administration of several BCS class II and IV anticancer drugs.

Opportunities and Challenges for Nanotherapeutics for the Aging Population

Nanotherapeutics utilize the properties of nanomaterials to alter the pharmacology of the drugs and therapies being transported, leading to changes in their biological disposition (absorption, distribution, cellular uptake, metabolism and elimination) and ultimately, their pharmacological effect. This provides an opportunity to optimize the pharmacology of drugs, particularly for those that are dependent on hepatic action. Old age is associated with changes in many pharmacokinetic processes which tend to impair drug efficacy and increase risk of toxicity. While these age-related changes are drug-specific they could be directly addressed using nanotechnology and precision targeting. The benefits of nanotherapeutics needs to be balanced against toxicity, with future use in humans dependent upon the gathering of information about the clearance and long-term safety of nanomaterials.

Assessment of genotoxicity of silver nanoparticles on lymphocyte cells of albino rats using comet assay

Silver nanoparticles, "AgNPs", represent a prominent nanoproduct, but most of the previous toxicity studies on its genotoxicity are still limited. The current study aimed to assess the genotoxicity of AgNPs on lymphocyte cells using comet assay and to study the recovery probability. It was conducted on 50 adult male albino rats divided into "Control group", 10 rats were injected intraperitoneal, "IP", with distilled water for 28 days, and "Test groups", 40 rats were injected "IP" with 13 ± 3 nm AgNPs for 28 days, subdivided into group I: 10 rats were injected with 2 mg/kg AgNPs, group Ia: 10 rats were injected with 2 mg/kg AgNPs and left for another 4 weeks without scarification, group II: 10 rats were injected with 4 mg/kg AgNPs, and group IIa: 10 rats were injected with 4 mg/kg and left for another 4 weeks without scarification. There was a highly significant decrease in head parameters with an increase in tail parameters in both groups I and II and in group II more than group I. Moreover, there was a highly significant increase in head parameters with a decrease in tail parameters in group Ia compared with the control group and group IIa. Comets were classified according to the tail intensity and according to visual scoring for DNA damage, which revealed different grades of DNA damage with a degree of reversibility after 4 weeks stoppage of exposure. It could be concluded that AgNPs were considered to cause harmful genotoxic effects to the human body in a dose-dependent manner.

Complex Factors and Challenges that Affect the Pharmacology, Safety and Efficacy of Nanocarrier Drug Delivery Systems

Major developments in nanomedicines, such as nanoparticles (NPs), nanosomes, and conjugates, have revolutionized drug delivery capabilities over the past four decades. Although nanocarrier agents provide numerous advantages (e.g., greater solubility and duration of systemic exposure) compared to their small-molecule counterparts, there is considerable inter-patient variability seen in the systemic disposition, tumor delivery and overall pharmacological effects (i.e., anti-tumor efficacy and unwanted toxicity) of NP agents. This review aims to provide a summary of fundamental factors that affect the disposition of NPs in the treatment of cancer and why they should be evaluated during preclinical and clinical development. Furthermore, this chapter will highlight some of the translational challenges associated with elements of NPs and how these issues can only be addressed by detailed and novel pharmacology studies.