Nanocarrier systems for delivery of siRNA to ovarian cancer tissues

Introduction: Novel therapeutic strategies have been investigated for ovarian cancer to reduce toxicity and to improve outcomes for patients. Short interfering RNA (siRNA), which directs the sequence-specific degradation of target mRNA and provides specificity of gene knockdown, represents a unique class of potential therapeutics for ovarian cancer. However, siRNA molecules are rapidly degraded in plasma and are unable to passively diffuse through cellular membranes. Nanocarriers can efficiently protect siRNA from in vivo degradation and are able to deliver these active macromolecules to tumor cells even after intravenous administration.

Areas covered: Strategies of gene therapy and the role of siRNA in ovarian cancer treatment are introduced, followed by an overview of nanocarriers for siRNA delivery, the advantages of the systems and the types of targeting to tumor cells. Classes of nanocarriers for delivery of siRNA, their functionalities and modalities are discussed with emphasis on the promising vehicles.

Expert opinion: Gene silencing therapy based on siRNA represents a possible opportunity for treatment of ovarian cancer patients. However, this approach requires selection of suitable nanocarriers that can safely and effectively deliver siRNA to the target site to induce its effect. Very little work has been done in this field; therefore, it is a good direction for future development.     

The use of quantitative analysis and Hansen solubility parameter predictions for the selection of excipients for lipid nanocarriers to be loaded with water soluble and insoluble compounds

The aim of these studies was to determine the miscibility of different API with lipid excipients to predict drug loading and encapsulation properties for the production of solid lipid nanoparticles and nanostructured lipid carriers. Five API exhibiting different physicochemical characteristics, viz., clarithromycin, efavirenz, minocycline hydrochloride, mometasone furoate, and didanosine were used and six solid lipids in addition to four liquid lipids were investigated. Determination of solid and liquid lipids with the best solubilization potential for each API were performed using a traditional shake-flask method and/or a modification thereof. Hansen solubility parameters of the API and different solid and liquid lipids were estimated from their chemical structure using Hiroshi Yamamoto’s molecular breaking method of Hansen Solubility Parameters in Practice software. Experimental results were in close agreement with solubility parameter predictions for systems with ΔδT < 4.0 MPa^1/2. A combination of Hansen solubility parameters with experimental drug-lipid miscibility tests can be successfully applied to predict lipids with the best solubilizing potential for different API prior to manufacture of solid lipid nanoparticles and nanostructured lipid carriers.     

In vivo study of mPEG–PCL as a nanocarriers for anti-inflammatory drug delivery of simvastatin

Purpose: In this study, methoxy poly (ethylene glycol)-poly (ε-caprolactone) (mPEG–PCL) di-block copolymers were synthesized. The purpose of this work is to investigate the in vivo anti-inflammatory effects of simvastatin-loaded micelles.

Methods: The structure of synthesized copolymers was characterized by using HNMR, FTIR, and GPC techniques. Simvastatin was encapsulated in micelles through a single-step nano-precipitation method, leading to the formation of simvastatin-loaded mPEG–PCL (simvastatin-mPEG–PCL) micelles. In this study, the anti-inflammatory effects of simvastatin/mPEG–PCL micelles versus indomethacin were investigated in acute inflammation-induced rats. The paw edema thickness was measured 1, 2, 3, and 4?h after injection of formulation. The inhibition of edema in various groups were calculated and reported by percentages.

Results: The results showed that the zeta potential of micelles was about ?14.9?±?0.47?mV and the average size was in range of 66.10?±?0.34?nm. Simvastatin was encapsulated in mPEG–PCL micelles with a loading capacity of 9.63?±?0.87% and an encapsulation efficiency of 64.20?±?0.79%. Simvastatin and simvastatin-mPEG–PCL micelles showed significant anti-inflammatory activity in the present study.

Conclusions: This study revealed that simvastatin and simvastatin/mPEG–PCL micelles both have anti-inflammatory effects and suggested that statins have potential anti-inflammatory activity along with their lipid lowering properties.     

纳米药物载体在中药制剂研发中的应用

纳米药物载体通常由天然或合成高分子材料制成，大小在10～1 000 nm ，因其具有靶向性、缓释性、载体材料可生物相容和降解等显著优点，已在药物制剂研发中得到广泛应用。近年来，中药纳米制剂发展迅速，作者通过查阅国内外文献，重点围绕毫微粒、脂质纳米粒、纳米乳、纳米胶束、纳米脂质体等几种典型的纳米载体的特性、制备及其在中药制剂研发中的应用进行综述。     

Cell-derived biomimetic nanocarriers for targeted cancer therapy: cell membranes and extracellular vesicles

Nanotechnology provides synthetic carriers for cancer drug delivery that protect cargos from degradation, control drug release and increase local accumulation at tumors. However, these non-natural vehicles display poor tumor targeting and potential toxicity and are eliminated by the immune system. Recently, biomimetic nanocarriers have been widely developed based on the concept of ‘mimicking nature.’ Among them, cell-derived biomimetic vehicles have become the focus of bionics research because of their multiple natural functions, such as low immunogenicity, long circulation time and targeting ability. Cell membrane-coated carriers and extracellular vesicles are two widely used cell-based biomimetic materials. Here, this review summarizes the latest progress in the application of these two biomimetic carriers in targeted cancer therapy. Their properties and performance are compared, and their future challenges and development prospects are discussed.     

基于生物可降解高分子的蛋白类药物纳米递送系统研究进展

生物可降解功能高分子纳米载药粒子具有良好的生物相容性,作为新型药物载体在疾病的诊断和治疗方面显示出巨大的应用价值。蛋白类药物最近在肿瘤免疫疗法及其他重大疾病中大放异彩,但是其载体技术的发展却相对滞后。本文从蛋白类药物递送方面综述了近年来生物可降解功能高分子作为蛋白类药物纳米载体的研究进展,并对开发具有更好应用研究前景的新型生物可降解功能高分子进行了展望。     

Hydrophobic ion pairing as a strategy to improve drug encapsulation into lipid nanocarriers for the cancer treatment

Introduction: Incorporation of anticancer drugs with low lipophilicity in lipid nanocarriers is usually low, which limits the utilization of this strategy in cancer therapy. However, the complexation of these drugs with lipophilic ion pairs containing ionizable groups has been reported to improve their incorporation in nanocarriers such as solid lipid nanoparticles (SLNs), nanostructured lipid nanocarriers (NLCs), and nanoemulsions (NEs). Therefore, those nanocarriers have shown an increase in efficacy and lower toxicity compared with the free drugs, particularly if the counter ion utilized has anticancer activity.

Areas covered: This review covers, from 1999 to the present, the utilization of the hydrophobic ion pair (HIP) approach to enhance the encapsulation of anticancer drugs in lipid nanostructured delivery systems, SLN, NLC, and NE; the benefits achieved; and challenges to improve the anticancer therapy.

Expert opinion: The HIP strategy has consistently demonstrated enhancement of the encapsulation efficiency in NLCs associated with increased anticancer activity of drugs such as doxorubicin, all-trans retinoic acid, methotrexate, vincristine and others. From this point on, conducting further physicochemical characterization studies of the formed ion pair as well as proceeding with the in vivo efficacy, toxicity and pharmacokinetics studies are expected.     

Preparation,Characterization, and Anticancer Effects of Capsaicin-Loaded Nanoliposomes

Background: Medicinal plants have proven their value as a source of molecules with therapeutic potential, and recent studies have shown that capsaicin has profound anticancer effects in several types of human cancers. However, its clinical use is handicapped due to its poor pharmacokinetics. This study aims to enhance capsaicin’s pharmacokinetic properties by loading the molecule into nanoliposomes model and testing its anticancer activity. Methods: Nanoliposomes were prepared using the thin-film method, and characteristics were examined followed by qualitative and quantitative analyses of encapsulation efficiency and drug loading using HPLC at different lipid/capsaicin ratios. Cell viability assay (MTT) was used to determine IC₅₀. Results: Capsaicin-loaded nanoliposomes showed optimum characteristics of morphology, particle size, zeta potential, and stability. In vitro anticancer activity of capsaicin and capsaicin-loaded nanoliposomes were compared against MCF7, MDA-MB-231, K562, PANC1, and A375 cell lines. Capsaicin-loaded nanoliposomes showed significant improvement in anticancer activity against cancers cell lines studied (p < 0.001), with increased selectivity against cancer cells compared to capsaicin. Conclusion: The encapsulated capsaicin nanoliposomes produced an improvement in pharmacokinetics properties, enhancing the anticancer activity and selectivity compared with capsaicin. This model seems to offer a potential for developing capsaicin formulations for the prevention and treatment of cancer.     

Development of Encapsulation Strategies and Composite Edible Films to Maintain Lactoferrin Bioactivity: A Review

Lactoferrin (LF) is a whey protein with various and valuable biological activities. For this reason, LF has been used as a supplement in formula milk and functional products. However, it must be considered that the properties of LF can be affected by technological treatments and gastrointestinal conditions. In this article, we have revised the literature published on the research done during the last decades on the development of various technologies, such as encapsulation or composite materials, to protect LF and avoid its degradation. Multiple compounds can be used to conduct this protective function, such as proteins, including those from milk, or polysaccharides, like alginate or chitosan. Furthermore, LF can be used as a component in complexes, nanoparticles, hydrogels and emulsions, to encapsulate, protect and deliver other bioactive compounds, such as essential oils or probiotics. Additionally, LF can be part of systems to deliver drugs or to apply certain therapies to target cells expressing LF receptors. These systems also allow improving the detection of gliomas and have also been used for treating some pathologies, such as different types of tumours. Finally, the application of LF in edible and active films can be effective against some contaminants and limit the increase of the natural microbiota present in meat, for example, becoming one of the most interesting research topics in food technology.