In vivo gene transfer using pDNA/chitosan/chondroitin sulfate ternary complexes: influence of chondroitin sulfate on the stability of freeze-dried complexes and transgene expression in vivo

Heparinoid Complex-Based Heparin-Binding Cytokines and Cell Delivery Carriers

Heparinoid is the generic term that is used for heparin, heparan sulfate (HS), and heparin-like molecules of animal or plant origin and synthetic derivatives of sulfated polysaccharides. Various biological activities of heparin/HS are attributed to their specific interaction and regulation with various heparin-binding cytokines, antithrombin (AT), and extracellular matrix (ECM) biomolecules. Specific domains with distinct saccharide sequences in heparin/HS mediate these interactions are mediated and require different highly sulfated saccharide sequences with different combinations of sulfated groups. Multivalent and cluster effects of the specific sulfated sequences in heparinoids are also important factors that control their interactions and biological activities. This review provides an overview of heparinoid-based biomaterials that offer novel means of engineering of various heparin-binding cytokine-delivery systems for biomedical applications and it focuses on our original studies on non-anticoagulant heparin-carrying polystyrene (NAC-HCPS) and polyelectrolyte complex-nano/microparticles (N/MPs), in addition to heparin-coating devices.

Polyelectrolyte Complexes of Natural Polymers and Their Biomedical Applications

Polyelectrolyte complexes (PECs), composed of natural and biodegradable polymers, (such as positively charged chitosan or protamine and negatively charged glycosaminoglycans (GAGs)) have attracted attention as hydrogels, films, hydrocolloids, and nano-/micro-particles (N/MPs) for biomedical applications. This is due to their biocompatibility and biological activities. These PECs have been used as drug and cell delivery carriers, hemostats, wound dressings, tissue adhesives, and scaffolds for tissue engineering. In addition to their comprehensive review, this review describes our original studies and provides an overview of the characteristics of chitosan-based hydrogel, including photo-cross-linkable chitosan hydrogel and hydrocolloidal PECs, as well as molecular-weight heparin (LH)/positively charged protamine (P) N/MPs. These are generated by electrostatic interactions between negatively charged LH and positively charged P together with their potential biomedical applications.

Naked pDNA Inhalation Powder Composed of Hyaluronic Acid Exhibits High Gene Expression in the Lungs

Gene therapy is a breakthrough treatment strategy against several intractable and lethal diseases that previously lacked established treatments. Viral and nonviral vectors have been studied to realize higher gene transfection efficiencies and to suppress the degradation of gene by nucleolytic enzymes in vivo. However, it is often the case that the addition of a vector results in adverse effects. In this study, we identified formulations of dry naked plasmid DNA (pDNA) powders with no vector showing significantly higher gene expression than pDNA solutions including vectors such as polyethylenimine (PEI) in the lungs of mice. We prepared the naked pDNA powders by spray-freeze-drying with various excipients. The gene expression of naked pDNA powders exceeded those of pDNA solutions containing PEI, naked pDNA solution, and reconstituted pDNA powder. Gene expression of each naked pDNA powder was dependent on the composition of excipients. Among them, the mice that were administered the pDNA powder composed of low-molecular-weight hyaluronic acid (LHA) as an excipient showed the highest gene expression. The lactate dehydrogenase activity and concentration of inflammatory cytokines in bronchoalveolar lavage fluid were comparable to those caused by ultrapure water. The results suggest that useful dry naked nucleic acid powders for inhalation could be created by optimizing the excipients, offering new insights into the development of pulmonary gene therapy.

In vitro and in vivo gene delivery using chitosan/hyaluronic acid nanoparticles: Influences of molecular mass of hyaluronic acid and lyophilization on transfection efficiency

BACKGROUND

Lyophilization is an effective method for preserving nonviral gene vectors. To improve the stability and transgene expression of lyophilized plasmid DNA (pDNA) complexes, we coated the surfaces of pDNA/chitosan complexes with hyaluronic acid (HA) of varying molecular masses. The transgene expression of pDNA/chitosan/HA ternary complexes was characterized in vitro and in vivo.

METHODS

pDNA complexes were lyophilized overnight and the resultant products with spongy, porous consistencies were stored at -30, 4 or 25°C for 2 weeks. Rehydrated complexes were characterized using gel retardation assays, aiming to confirm complex formation, measure particle size and evaluate zeta potential, as well as conduct luciferase gene reporter assays. The anti-tumor effects of pDNA ternary complexes were evaluated using suicide gene (pTK) coding thymidine kinase in Huh7-implanted mice.

RESULTS

Transfection efficiencies of pDNA/chitosan/HA ternary complexes were dependent on the average molecular masses of HA. The coating of pDNA/chitosan complexes with HA maintained the cellular transfection efficiencies of lyophilized pDNA ternary complexes. Furthermore, intratumoral injection of lyophilized, rehydrated pDNA ternary complexes into tumor-bearing mice showed a significant suppression of tumor growth.

CONCLUSIONS

The coating of pDNA/chitosan complexes with high-molecular-weight HA augmented the stability and cellular transfection ability of the complexes after lyophilization-rehydration.

Enhanced effect of fibroblast growth factor-2-containing dalteparin/protamine nanoparticles on hair growth

Purpose

Although treatments for alopecia are in high demand, not all treatments are safe and reliable. Dalteparin/protamine nanoparticles (D/P NPs) can effectively carry growth factors (GFs) such as fibroblast GF (FGF)-2. The purpose of this study was to identify the effects of FGF-2-containing D/P NPs (FGF-2&D/P NPs) on hair growth.

Patients and methods

In this study, the participants were 12 volunteers with thin hair. One milliliter of FGF-2 (100 ng/mL) and D/P NPs (56 μg/mL) was applied and massaged on the skin of the scalp by the participants twice a day. They were evaluated for 6 months. Participants were photographed using a digital camera for general observation and a hair diagnosis system for measuring hair diameter.

Results

The mean diameter of the hairs was significantly higher following the application of FGF-2&D/P NPs for 6 months. Objective improvements in thin hair were observed in two cases. Nine participants experienced greater bounce and hair resilience.

Conclusion

The transdermal application of FGF-2&D/P NPs to the scalp can be used as a new treatment for alopecia.

Biomedical application of low molecular weight heparin/protamine nano/micro particles as cell- and growth factor-carriers and coating matrix

Low molecular weight heparin (LMWH)/protamine (P) nano/micro particles (N/MPs) (LMWH/P N/MPs) were applied as carriers for heparin-binding growth factors (GFs) and for adhesive cells including adipose-derived stromal cells (ADSCs) and bone marrow-derived mesenchymal stem cells (BMSCs). A mixture of LMWH and P yields a dispersion of N/MPs (100 nm–3 μm in diameter). LMWH/P N/MPs can be immobilized onto cell surfaces or extracellular matrix, control the release, activate GFs and protect various GFs. Furthermore, LMWH/P N/MPs can also bind to adhesive cell surfaces, inducing cells and LMWH/P N/MPs-aggregate formation. Those aggregates substantially promoted cellular viability, and induced vascularization and fibrous tissue formation in vivo. The LMWH/P N/MPs, in combination with ADSCs or BMSCs, are effective cell-carriers and are potential promising novel therapeutic agents for inducing vascularization and fibrous tissue formation in ischemic disease by transplantation of the ADSCs and LMWH/P N/MPs-aggregates. LMWH/P N/MPs can also bind to tissue culture plates and adsorb exogenous GFs or GFs from those cells. The LMWH/P N/MPs-coated matrix in the presence of GFs may provide novel biomaterials that can control cellular activity such as growth and differentiation. Furthermore, three-dimensional (3D) cultures of cells including ADSCs and BMSCs using plasma-medium gel with LMWH/P N/MPs exhibited efficient cell proliferation. Thus, LMWH/P N/MPs are an adequate carrier both for GFs and for stromal cells such as ADSCs and BMSCs, and are a functional coating matrix for their cultures.