Sustained Drug Release from Smart Nanoparticles in Cancer Therapy: A Comprehensive Review

Although nanomedicine has been highly investigated for cancer treatment over the past decades, only a few nanomedicines are currently approved and in the market; making this field poorly represented in clinical applications. Key research gaps that require optimization to successfully translate the use of nanomedicines have been identified, but not addressed; among these, the lack of control of the release pattern of therapeutics is the most important. To solve these issues with currently used nanomedicines (e.g., burst release, systemic release), different strategies for the design and manufacturing of nanomedicines allowing for better control over the therapeutic release, are currently being investigated. The inclusion of stimuli-responsive properties and prolonged drug release have been identified as effective approaches to include in nanomedicine, and are discussed in this paper. Recently, smart sustained release nanoparticles have been successfully designed to safely and efficiently deliver therapeutics with different kinetic profiles, making them promising for many drug delivery applications and in specific for cancer treatment. In this review, the state-of-the-art of smart sustained release nanoparticles is discussed, focusing on the design strategies and performances of polymeric nanotechnologies. A complete list of nanomedicines currently tested in clinical trials and approved nanomedicines for cancer treatment is presented, critically discussing advantages and limitations with respect to the newly developed nanotechnologies and manufacturing methods. By the presented discussion and the highlight of nanomedicine design criteria and current limitations, this review paper could be of high interest to identify key features for the design of release-controlled nanomedicine for cancer treatment.

Effects of inhalable gene transfection as a novel gene therapy for non-small cell lung cancer and malignant pleural mesothelioma

Gene therapy using vectors has attracted attention in recent years for the treatment of cancers caused by gene mutations. Besides, new treatments are imperative for lung cancer, including non-small cell lung cancer (NSCLC) and malignant pleural mesothelioma (MPM), due to its high mortality. We developed a minimally invasive and orally inhalable tumor suppressor gene drug (SFD-p16 and SFD-p53) with non-viral vectors for lung cancer treatment by combining tumor suppressor genes with an inhalant powder that can deliver active ingredients directly to the lung. We used NSCLC (A549 and H1299) and MPM (H2052) cell lines in an air–liquid interface culture. Transfection of A549 and H2052 cells with SFD-p16 significantly increased p16 mRNA expression levels and decreased cell proliferation in both cell lines. Similar results were obtained with transfection of H1299 with the inhalable gene drug SFD-p53. In an in vivo experiment, a mouse model of lung cancer with orthotopically transplanted luciferase-expressing A549 cells was subjected to intratracheal insufflation of SFD-p16. Consequently, SFD-p16 effectively and directly affected lung cancer. This study suggests that inhalable gene drugs are effective treatments for NSCLC and MPM. We expect inhalable gene drugs to present a novel gene therapy agent for lung cancer that patients can self-administer.

A novel method for the development of plasmid DNA-loaded nanoliposomes for cancer gene therapy

We aimed to develop a simple yet novel method to prepare plasmid DNA-loaded nanoliposomes for cancer gene therapy. Murine interleukin-12 (mIL-12) pDNA-loaded nanoliposomes were prepared via novel freeze-drying of a monophase solution method. The physicochemical characteristics, cytotoxicity, and transfection efficiency of the prepared nanoliposomes in murine CT-26 colon carcinoma cells were evaluated. Furthermore, tumor progression and survival rate in CT-26 colon carcinoma-bearing BALB/c mice subsequent to direct intratumoral injections were investigated over a period of 40 days. Using this preparation method, nanoliposomes with particle size of around 300 nm and zeta potential of 96.5 mV were obtained. The transmission electron microscope results showed that the liposomes were nano-sized and almost spherical. The agarose gel retardation assay revealed the pDNA encapsulation in the nanoliposomes. The nanoliposomes with 72.4% encapsulation efficiency and low cell toxicity could significantly improve mIL-12 expression by approximately 25-fold relative to the naked mIL-12 pDNA. There was a significant tumor growth inhibition after repeated injections of mIL-12 pDNA-loaded nanoliposomes. This is the first study on the freeze-drying of a monophase solution method as a simple yet novel technique for the preparation of pDNA-loaded nanoliposomes. Given the ease of preparation method and promising in vitro and in vivo characteristics, this investigation demonstrates advances in pDNA lipid formulation for cancer gene therapy.

Future Prospects of Gene Therapy for Friedreich's Ataxia

Friedreich's ataxia is an autosomal recessive neurogenetic disease that is mainly associated with atrophy of the spinal cord and progressive neurodegeneration in the cerebellum. The disease is caused by a GAA-expansion in the first intron of the frataxin gene leading to a decreased level of frataxin protein, which results in mitochondrial dysfunction. Currently, there is no effective treatment to delay neurodegeneration in Friedreich's ataxia. A plausible therapeutic approach is gene therapy. Indeed, Friedreich's ataxia mouse models have been treated with viral vectors en-coding for either FXN or neurotrophins, such as brain-derived neurotrophic factor showing promising results. Thus, gene therapy is increasingly consolidating as one of the most promising therapies. However, several hurdles have to be overcome, including immunotoxicity and pheno-toxicity. We review the state of the art of gene therapy in Friedreich's ataxia, addressing the main challenges and the most feasible solutions for them.

The Development of Functional Non-Viral Vectors for Gene Delivery

Gene therapy is manipulation in/of gene expression in specific cells/tissue to treat diseases. This manipulation is carried out by introducing exogenous nucleic acids, such as DNA or RNA, into the cell. Because of their negative charge and considerable larger size, the delivery of these molecules, in general, should be mediated by gene vectors. Non-viral vectors, as promising delivery systems, have received considerable attention due to their low cytotoxicity and non-immunogenicity. As research continued, more and more functional non-viral vectors have emerged. They not only have the ability to deliver a gene into the cells but also have other functions, such as the performance of fluorescence imaging, which aids in monitoring their progress, targeted delivery, and biodegradation. Recently, many reviews related to non-viral vectors, such as polymers and cationic lipids, have been reported. However, there are few reviews regarding functional non-viral vectors. This review summarizes the common functional non-viral vectors developed in the last ten years and their potential applications in the future. The transfection efficiency and the transport mechanism of these materials were also discussed in detail. We hope that this review can help researchers design more new high-efficiency and low-toxicity multifunctional non-viral vectors, and further accelerate the progress of gene therapy.

Cancer drug delivery in the nano era: An overview and perspectives (Review)

Nanomaterials are increasingly used as drug carriers for cancer therapy. Nanomaterials also appeal to researchers in the areas of cancer diagnosis and biomarker discovery. Several antitumor nanodrugs are currently being tested in preclinical and clinical trials and show promise in therapeutic and other settings. We review the development of nanomaterial drug carriers, including liposomes, polymer nanoparticles, dendritic polymers, and nanomicelles, for the diagnosis and treatment of various cancers. The prospects of nanomaterials as drug carriers for future clinical applications are also discussed.

Gold nanoparticle-conjugated heterogeneous polymer brush-wrapped cellulose nanocrystals prepared by combining different controllable polymerization techniques for theranostic applications

Spindly cellulose nanocrystals were coated with Au nanoparticle-conjugated heterogeneous polymer brushes prepared via different controllable polymerization.