Mimicking the Biology of Engineered Protein and mRNA Nanoparticle Delivery Using a Versatile Microfluidic Platform

To investigate the delivery of next-generation macromolecular drugs, such as engineered proteins and mRNA-containing nanoparticles, there is an increasing push towards the use of physiologically relevant disease models that incorporate human cells and do not face ethical dilemmas associated with animal use. Here, we illustrate the versatility and ease of use of a microfluidic platform for studying drug delivery using high-resolution microscopy in 3D. Using this microfluidic platform, we successfully demonstrate the specific targeting of carbonic anhydrase IX (CAIX) on cells overexpressing the protein in a tumor-mimicking chip system using affibodies, with CAIX-negative cells and non-binding affibodies as controls. Furthermore, we demonstrate this system’s feasibility for testing mRNA-containing biomaterials designed to regenerate bone defects. To this end, peptide- and lipid-based mRNA formulations were successfully mixed with colloidal gelatin in microfluidic devices, while translational activity was studied by the expression of a green fluorescent protein. This microfluidic platform enables the testing of mRNA delivery from colloidal biomaterials of relatively high densities, which represents a first important step towards a bone-on-a-chip platform. Collectively, by illustrating the ease of adaptation of our microfluidic platform towards use in distinct applications, we show that our microfluidic chip represents a powerful and flexible way to investigate drug delivery in 3D disease-mimicking culture systems that recapitulate key parameters associated with in vivo drug application.

Efficient intracellular delivery of proteins by a multifunctional chimaeric peptide in vitro and in vivo

Protein delivery with cell-penetrating peptide is opening up the possibility of using targets inside cells for therapeutic or biological applications; however, cell-penetrating peptide-mediated protein delivery commonly suffers from ineffective endosomal escape and low tolerance in serum, thereby limiting in vivo efficacy. Here, we present an intracellular protein delivery system consisting of four modules in series: cell-penetrating peptide, pH-dependent membrane active peptide, endosome-specific protease sites and a leucine zipper. This system exhibits enhanced delivery efficiency and serum tolerance, depending on proteolytic cleavage-facilitated endosomal escape and leucine zipper-based dimerisation. Intravenous injection of protein phosphatase 1B fused with this system successfully suppresses the tumour necrosis factor-α-induced systemic inflammatory response and acetaminophen-induced acute liver failure in a mouse model. We believe that the strategy of using multifunctional chimaeric peptides is valuable for the development of cell-penetrating peptide-based protein delivery systems, and facilitate the development of biological macromolecular drugs for use against intracellular targets.

Advances in Oral Chitosan Based Nano Delivery System for colon Targeted Drug Delivery in Inflammatory Bowel Disease

Nanomaterials can be used as drug carriers with multiple features, including target delivery triggered by environmental, pH, thermal responses, enhanced biocompatibility, and the ability to cross the blood-brain barrier. Chitosan (CS) is a natural polysaccharide largely obtained from marine crustaceans. It provides drug delivery vector for therapeutic CS and diagnostic CS, owing to its biocompatibility, biodegradability, low toxicity, and structural variability. Derivatives of CS such as quaternized CS, thiolated CS and carboxylated CS have enhanced its effectiveness in oral absorption of macromolecular drugs. This review discusses different forms of nanomaterials generated from CS and its derivatives for controlled drug delivery.

Trends in liposomal nanocarrier strategies for the oral delivery of biologics

The number of approved macromolecular drugs such as peptides, proteins and antibodies steadily increases. Since drugs with high molecular weight are commonly not suitable for oral delivery, research on carrier strategies enabling oral administration is of vital interest. In past decades, nanocarriers, in particular liposomes, have been exhaustively investigated as oral drug-delivery platform. Despite their successful application as parenteral delivery vehicles, liposomes have up to date not succeeded for oral administration. However, a plenitude of approaches aiming to increase the oral bioavailability of macromolecular drugs administered by liposomal formulations has been published. Here, we summarize the strategies published in the last 10 years (vaccine strategies excluded) with a main focus on strategies proven efficient in animal models.

EPR-Effect Enhancers Strongly Potentiate Tumor-Targeted Delivery of Nanomedicines to Advanced Cancers: Further Extension to Enhancement of the Therapeutic Effect

For more than three decades, enhanced permeability and retention (EPR)-effect-based nanomedicines have received considerable attention for tumor-selective treatment of solid tumors. However, treatment of advanced cancers remains a huge challenge in clinical situations because of occluded or embolized tumor blood vessels, which lead to so-called heterogeneity of the EPR effect. We previously developed a method to restore impaired blood flow in blood vessels by using nitric oxide donors and other agents called EPR-effect enhancers. Here, we show that two novel EPR-effect enhancers—isosorbide dinitrate (ISDN, Nitrol®) and sildenafil citrate—strongly potentiated delivery of three macromolecular drugs to tumors: a complex of poly(styrene-co-maleic acid) (SMA) and cisplatin, named Smaplatin® (chemotherapy); poly(N-(2-hydroxypropyl)methacrylamide) polymer-conjugated zinc protoporphyrin (photodynamic therapy and imaging); and SMA glucosamine-conjugated boric acid complex (boron neutron capture therapy). We tested these nanodrugs in mice with advanced C26 tumors. When these nanomedicines were administered together with ISDN or sildenafil, tumor delivery and thus positive therapeutic results increased two- to four-fold in tumors with diameters of 15 mm or more. These results confirmed the rationale for using EPR-effect enhancers to restore tumor blood flow. In conclusion, all EPR-effect enhancers tested showed great potential for application in cancer therapy.

Nanodrug Delivery Systems Modulate Tumor Vessels to Increase the Enhanced Permeability and Retention Effect

The use of nanomedicine for antitumor therapy has been extensively investigated for a long time. Enhanced permeability and retention (EPR) effect-mediated drug delivery is currently regarded as an effective way to bring drugs to tumors, especially macromolecular drugs and drug-loaded pharmaceutical nanocarriers. However, a disordered vessel network, and occluded or embolized tumor blood vessels seriously limit the EPR effect. To augment the EPR effect and improve curative effects, in this review, we focused on the perspective of tumor blood vessels, and analyzed the relationship among abnormal angiogenesis, abnormal vascular structure, irregular blood flow, extensive permeability of tumor vessels, and the EPR effect. In this commentary, nanoparticles including liposomes, micelles, and polymers extravasate through the tumor vasculature, which are based on modulating tumor vessels, to increase the EPR effect, thereby increasing their therapeutic effect.

The Two Faces of Exosomes in Parkinson’s Disease: From Pathology to Therapy

Accumulating evidence suggests that exosomes play a key role in Parkinson’s disease (PD). Exosomes may contribute to the PD progression facilitating the spread of pathological alpha-synuclein or activating immune cells. Glial cells also release exosomes, and transmission of exosomes derived from activated glial cells containing inflammatory mediators may contribute to the propagation of the neuroinflammatory response. Glia-to-neuron transmission of exosomes containing alpha-synuclein may contribute to alpha-synuclein propagation and neurodegeneration. Additionally, miRNAs can be transmitted among cells via exosomes inducing changes in the genetic program of the target cell contributing to PD progression. Exosomes also represent a promising drug delivery system. The brain is a difficult target for drugs of all classes because the blood-brain barrier excludes most macromolecular drugs. One of the major challenges is the development of vehicles for robust delivery to the brain. Targeted exosomes may have the potential for delivering therapeutic agents, including proteins and gene therapy molecules, into the brain. This review summarizes recent advances in the role of exosomes in PD pathology progression and their potential use as drug delivery system for PD treatment, the two faces of the exosomes in PD.

Bioadhesive polymers, permeation enhancers and types of dosage forms for buccal drug delivery

The buccal delivery is defined as the drug administration through the mucosal membranes lining the cheeks (buccal mucosa). The main impediment to the use of many hydrophilic macromolecular drugs as potential therapeutic agents is their inadequate and erratic oral absorption. Based on our current understanding of biochemical and physiological aspects of absorption and metabolism of many biotechnologically produced drugs, they cannot be delivered effectively through the conventional oral route. Because after oral administration many drugs are subjected to pre-systemic clearance extensive in the liver, which often leads to a lack of significant correlation between membrane permeability, absorption and bioavailability. Difficulties associated with the parenteral delivery and poor oral bioavailability provided the impetus for exploring alternative routes for the delivery of such drugs. This review covers the advantages, disadvantages of buccal delivery, drug and excipient selection especially bioadhesive polymers and permeation enhancers, and further a list of drugs developed as various dosage forms for buccal route of administration. Keywords: Buccal delivery, bioadhesive/mucoadhesive, permeation enhancer, dosage forms.