Nanoscale delivery systems for multiple drug combinations in cancer

Advances in nanomedical applications: diagnostic, therapeutic, immunization, and vaccine production

In the last decades, nanotechnology-based tools started to draw the attention of research worldwide. They offer economic, rapid, effective, and highly specific solutions for most medical issues. As a result, the international demand of nanomaterials is expanding very rapidly. It was estimated that the market of nanomaterials was about $2.6 trillion in 2015. In medicine, various applications of nanotechnology proved their potential to revolutionize medical diagnosis, immunization, treatment, and even health care products. The loading substances can be coupled with a large set of nanoparticles (NPs) by many means: chemically (conjugation), physically (encapsulation), or via adsorption. The use of the suitable loading nanosubstance depends on the application purpose. They can be used to deliver various chemicals (drugs, chemotherapeutic agents, or imaging substances), or biological substances (antigens, antibodies, RNA, or DNA) through endocytosis. They can even be used to deliver light and heat to their target cells when needed. The present review provides a brief overview about the structure and shape of available NPs and discusses their applications in the medical sciences.

Magnesium-Engineered Silica Framework for pH-Accelerated Biodegradation and DNAzyme-Triggered Chemotherapy

Inorganic nanocarriers have shown their high performance in disease theranostics in preclinical animal models and further great prospects for clinical translation. However, their dissatisfactory biodegradability and pre-drug leakage with nonspecificity to lesion sites significantly hinders the possible clinical translation. To solve these two critical issues, a framework-engineering strategy is introduced to simultaneously achieve enhanced biodegradability and controllable drug releasing, based on the mostly explored mesoporous silica-based nanosystems. The framework of mesoporous silica is engineered by direct Mg doping via a generic dissolution and regrowth approach, and it can transform into the easy biodegradation of magnesium silicate nanocarriers with simultaneous on-demand drug release. Such magnesium silicate nanocarriers can respond to the mild acidic environment of tumor tissue, causing the fast breaking up and biodegradation of the silica framework. More interesting, the released Mg²⁺ can further activate Mg²⁺ -dependent DNAzyme on the surface of hollow mesoporous magnesium silicate nanoparticles (HMMSNs) to cleave the RNA-based gatekeeper, which further accelerates the release of loaded anticancer drugs. Therefore, enhanced anticancer efficiency of chemotherapeutic drugs assisted by the biodegradable intelligent HMMSNs is achieved. The high biocompatibility of nanocarriers and biodegradation products is demonstrated and can be easily excreted via feces and urine guaranteeing their further clinical translation.

Development of Sustained Release "NanoFDC (Fixed Dose Combination)" for Hypertension - An Experimental Study

Objectives

The present study was planned to formulate, characterize and evaluate the pharmacokinetics of a novel “NanoFDC” comprising three commonly prescribed anti-hypertensive drugs, hydrochlorothiazide (a diuretic), candesartan (ARB) and amlodipine (a calcium channel blocker).

Basic Methods

The candidate drugs were loaded in Poly (DL-lactide-co-gycolide) (PLGA) by emulsion- diffusion-evaporation method. The formulations were evaluated for their size, morphology, drug loading and in vitro release individually. Single dose pharmacokinetic profiles of the nanoformulations alone and in combination, as a NanoFDC, were evaluated in Wistar rats.

Results

The candidate drugs encapsulated inside PLGA showed entrapment efficiencies ranging from 30%, 33.5% and 32% for hydrochlorothiazide, candesartan and amlodipine respectively. The nanoparticles ranged in size from 110 to 180 nm. In vitro release profile of the nanoformulation showed 100% release by day 6 in the physiological pH 7.4 set up with PBS (phosphate buffer saline) and by day 4-5 in the intestinal pH 1.2 and 8.0 set up SGF (simulated gastric fluid) and SIF (simulated intestinal fluid) respectively. In pharmacokinetic analysis a sustained-release for 6 days and significant increase in the mean residence time (MRT), as compared to the respective free drugs was noted [MRT of amlodipine, hydrochlorothiazide and candesartan changed from 8.9 to 80.59 hours, 11 to 69.20 hours and 9 to 101.49 hours respectively].

Conclusion

We have shown for the first time that encapsulating amlodipine, hydrochlorothiazide and candesartan into a single nanoformulation, to get the “NanoFDC (Fixed Dose Combination)” is a feasible strategy which aims to decrease pill burden.

Multifunctional nanoparticles for targeted delivery of immune activating and cancer therapeutic agents

Nanoparticles (NPs) have been extensively investigated for applications in both experimental and clinical settings to improve delivery efficiency of therapeutic and diagnostic agents. Most recently, novel multifunctional nanoparticles have attracted much attention because of their ability to carry diverse functionalities to achieve effective synergistic therapeutic treatments. Multifunctional NPs have been designed to co-deliver multiple components, target the delivery of drugs by surface functionalization, and realize therapy and diagnosis simultaneously. In this review, various materials of diverse chemistries for fabricating multifunctional NPs with distinctive architectures are discussed and compared. Recent progress involving multifunctional NPs for immune activation, anticancer drug delivery, and synergistic theranostics is the focus of this review. Overall, this comprehensive review demonstrates that multifunctional NPs have distinctive properties that make them highly suitable for targeted therapeutic delivery in these areas.