Design and evaluation of thioalkylated mannose-modified dendrimer (G3)/α-cyclodextrin conjugates as antigen-presenting cell-selective siRNA carriers

Mannose-methyl-β-cyclodextrin suppresses tumor growth by targeting both colon cancer cells and tumor-associated macrophages

Methylated β-cyclodextrin (MβCD) can extract cholesterol from lipid rafts and induce apoptosis in cancer cells by inhibiting activation of the PI3K-Akt-Bad pathway. In this study, we modified MβCD with mannose (Man-MβCD) and assessed its in vitro and in vivo potential for targeting colon cancer cells expressing the mannose receptor (MR) and tumor-associated macrophages (TAM). Man-MβCD showed a significantly greater level of cellular association with colon-26 cells and M2 macrophages, and much more prominent anticancer activity than that of MβCD against MR-positive colon-26 cells. These results revealed that autophagy was the main mechanism of cell death associated with Man-MβCD. Furthermore, compared with MβCD, Man-MβCD significantly reduced tumor development following intravenous delivery to tumor-bearing mice, with no apparent side effects. Thus, Man-MβCD has the potential to be a novel anticancer drug.

Novel Approaches in the Immunotherapy of Multiple Sclerosis: Cyclization of Myelin Epitope Peptides and Conjugation with Mannan

Multiple Sclerosis (MS) is a serious autoimmune disease. The patient in an advanced state of the disease has restrained mobility and remains handicapped. It is therefore understandable that there is a great need for novel drugs and vaccines for the treatment of MS. Herein we summarise two major approaches applied for the treatment of the disease using peptide molecules alone or conjugated with mannan. The first approach focuses on selective myelin epitope peptide or peptide mimetic therapy alone or conjugated with mannan, and the second on immune-therapy by preventing or controlling disease through the release of appropriate cytokines. In both approaches the use of cyclic peptides offers the advantage of increased stability from proteolytic enzymes. In these approaches, the synthesis of myelin epitope peptides conjugated to mannan is of particular interest as this was found to protect mice against experimental autoimmune encephalomyelitis, an animal model of MS, in prophylactic and therapeutic protocols. Protection was peptide-specific and associated with reduced antigen-specific T cell proliferation. The aim of the studies of these peptide epitope analogs is to understand their molecular basis of interactions with human autoimmune T-cell receptor and a MS-associated human leucocyte antigen (HLA)-DR2b. This knowledge will lead the rational design to new beneficial non-peptide mimetic analogs for the treatment of MS. Some issues of the use of nanotechnology will also be addressed as a future trend to tackle the disease. We highlight novel immunomodulation and vaccine-based research against MS based on myelin epitope peptides and strategies developed in our laboratories.

Twenty Years of Research on Cyclodextrin Conjugates with PAMAM Dendrimers

Recently, the number of gene and oligonucleotide drugs are increasing. Of various drug delivery systems (DDSs) for gene and oligonucleotide drugs, few examples of the clinical application of polymer as drug carriers are known, despite development of the novel polymers has been progressing. Cyclodextrin (CD) conjugates with starburst polyamidoamine (PAMAM) dendrimer (CDEs), as a new type of polymer-based carriers, were first published in 2001. After that, galactose-, lactose-, mannose-, fucose-, folate-, and polyethyleneglycol (PEG)-appended CDEs have been prepared for passive and active targeting for gene, oligonucleotide, and low-molecular-weight drugs. PEG-appended CDE formed polypsuedorotaxanes with α-CD and γ-CD, which are useful for a sustained release system of gene and oligonucleotide drugs. Interestingly, CDEs were found to have anti-inflammatory effects and anti-amyloid effects themselves, which have potential as active pharmaceutical ingredients. Most recently, CDE is reported to be a useful Cas9-RNA ribonucleoproteins (Cas9 RNP) carrier that induces genome editing in the neuron and brain. In this review, the history and progression of CDEs are overviewed.

Cyclodextrin-Based Functional Glyconanomaterials

Cyclodextrins (CDs) have long occupied a prominent position in most pharmaceutical laboratories as "off-the-shelve" tools to manipulate the pharmacokinetics of a broad range of active principles, due to their unique combination of biocompatibility and inclusion abilities. The development of precision chemical methods for their selective functionalization, in combination with "click" multiconjugation procedures, have further leveraged the nanoscaffold nature of these oligosaccharides, creating a direct link between the glyco and the nano worlds. CDs have greatly contributed to understand and exploit the interactions between multivalent glycodisplays and carbohydrate-binding proteins (lectins) and to improve the drug-loading and functional properties of nanomaterials through host-guest strategies. The whole range of capabilities can be enabled through self-assembly, template-assisted assembly or covalent connection of CD/glycan building blocks. This review discusses the advancements made in this field during the last decade and the amazing variety of functional glyconanomaterials empowered by the versatility of the CD component.

Potential therapeutic application of dendrimer/cyclodextrin conjugates with targeting ligands as advanced carriers for gene and oligonucleotide drugs

Despite the recent approval of some gene medicines and nucleic acid drugs, further improvement of delivery techniques for these drugs is strongly required. Several delivery technologies for these drugs have been developed, in other words, viral and two types of nonviral (lipofection and polyfection) vectors. Among the polyfection system, the potential use of various cyclodextrin (CyD) derivatives and CyD-appended polymers as carriers for gene and nucleic acid drugs has been demonstrated. The polyamidoamine dendrimer (G3) conjugates with α-CyD (α-CDE (G3)) have been reported to possess noteworthy properties as DNA and nucleic acid drugs carriers. This review will focus on the attempts to develop such cell-specific drug carriers by preparing polyethylene glycol, galactose, lactose, mannose, fucose and folic acid-appended α-CDEs as tissue and cell-selective carriers of gene and nucleic acid drugs.

Potential Use of Cyclodextrins as Drug Carriers and Active Pharmaceutical Ingredients

Cyclodextrins (CyDs) are extensively used in various fields, and especially have been widely utilized as pharmaceutical excipients and drug carriers in the pharmaceutical field. Owing to the multi-functional and biocompatible characteristics, CyDs can improve the undesirable properties of drug molecules. This review outlines the current application of CyDs in pharmaceutical formulations, focusing on their use as CyD-based drug carriers for several kinds of drugs. Additionally, CyDs have great potential as active pharmaceutical ingredients against various diseases with few side effects.

Recent advances in siRNA delivery

In the 1990s an unexpected gene-silencing phenomena in plants, the later called RNA interference (RNAi), perplexed scientists. Following the proof of activity in mammalian cells, small interfering RNAs (siRNAs) have quickly crept into biomedical research as a new powerful tool for the potential treatment of different human diseases based on altered gene expression. In the past decades, several promising data from ongoing clinical trials have been reported. However, despite surprising successes in many pre-clinical studies, concrete obstacles still need to be overcome to translate therapeutic siRNAs into clinical reality. Here, we provide an update on the recent advances of RNAi-based therapeutics and highlight novel synthetic platforms for the intracellular delivery of siRNAs.