Natural Starch in Biomedical and Food Industry: Perception and Overview

Utilization of native starch is increasing globally because of its wide distribution and natural occurrence. Starch is mainly abundant in tubers and food grains. Scientific research on starch is increasing in recent years due to its unique physiochemical and biomedical properties. Native starch is an emerging biopolymer and copolymer in the biomedical and pharmaceutical areas due to its renewability, biocompatibility, biodegradability, and relative inexpensiveness. Today, there is an increasing interest in natural starches to design and produce diverse products due to their pertinent structural properties and non-toxicity. Due to these attributes, these natural polymers are becoming functional core materials in the biomedical industry, construction materials, medicine industry, food industry, food packaging, and carrier for active drugs. In this paper, we mainly attempt to analyze the physicochemical attributions and the biomedical applications on native or non-conventional starches obtained from the natural botanical sources.

Adhesive Drug Delivery Systems Based on Polyelectrolyte Complex Nanoparticles (PEC NP) for Bone Healing

BACKGROUND

In this contribution an overview is given on own work concerning drug loaded Polyelectrolyte Complex (PEC) Nanoparticles (NP) used to functionalize Bone Substitute Materials (BSM) for the therapy of bone defects associated with systemic bone diseases. In this context, drug loaded PEC NP have certain advantages, which are exemplarily summarized herein.

METHODS

Concerning preparative methods PEC NP were fabricated by controlled mixing of polycation and polyanion solutions and integration of charged drugs during and after mixing. Control was taken on the stoichiometric ratio related to cationic and anionic repeating units, which was chosen close to zero for the final applied PEC NP. Concerning analytical methods a couple of physical-chemical methods were applied like colloid titration, Dynamic Light Scattering (DLS), Scanning Force Microscopy (SFM), Fourier Transform infrared (FTIR) spectroscopy, Ultraviolet-Visible (UV-VIS) and Circular Dichroism (CD) spectroscopy to characterize colloid stability, adhesiveness, drug loading and release of PEC NP. Moreover, standard biochemical and microbiological assays were applied.

CONCLUSION

Drug loaded PEC NP consist of oppositely charged biorelated Polyelectrolytes (PEL) like ionic polysaccharides or ionic polypeptides and also synthetic PEL, which are mixed and processed in aqueous media. At first, freshly prepared drug/PEC NP exhibit time dependent colloidal stability in the range of weeks and months, which enables and simplifies storage, transport and application in the medical field. Secondly, after deposition and drying of drug/PEC NP a local wet adhesive PEC matrix at the BSM remains in contact to relevant aqueous media (e.g. buffer, cell culture medium), which minimizes asepsis, systemic toxicity, immune or inflammatory reaction. Thirdly, cell compatible PEC NP coatings were identified, which showed only minimal effects on various relevant bone related cells due to biorelateness, complexation, local confinement and low surface area. Fourthly, PEC NP elute drugs for bone healing like bisphosphonates, antibiotics and growth factors (e.g. bone morphogenetic proteins) in delayed and sustained manner. Moreover, the onset of elution could be triggered by thermoresponsive PEL via temperature increase giving clinicians a tool into hand allowing spatiotemporal drug release on demand. Finally, drug/PEC NP could be integrated into commercial or still developed allotropic stabilizing or defect filling BSM systems.

Hyaluronate-Lipid Nanohybrids: Fruitful Harmony in Cancer Targeting

Significant research efforts have been concerned over the past few years to design carrier systems that could specifically deliver active agents to the tumor sites, with the purposes of maximizing the therapeutic benefits and minimizing the toxic side-effects. Hyaluronic acid is a type of polysaccharide that has been extensively studied as a selective targeting ligand to cancerous cells that overexpress its specific receptor CD44. The aim of this review is to highlight the role of HA in cancer, focusing on the recent advances of HA-functionalized lipid nanoparticles towards cancer therapy and imaging.

Ligand-modified Biopolymeric Nanoparticles as Efficient Tools for Targeted Cancer Therapy

Non-specific distribution of chemotherapeutic agents in the body where they affect both cancer as well as normal cells resulting in serious side effects is the major reason for the high mortality rate of cancer. Thus, there is a need for developing targeted delivery strategies specially employing nanoplatform-based cancer therapies that provide specific targeting to tumor cells. In this regard, biopolymeric nanoplatforms such as liposomes, protein- and polysaccharide- based nanoparticles have gained more attention due to their biocompatibility, biodegradability and less toxicity. In terms of targeting, monoclonal antibodies (mAbs), folic acid (FA) and transferrin (Tf) can be considered as the moieties to be attached to the nanoplatforms to deliver their payload to its site of action. This review article focuses on the recent progress in the field of targeted drug and gene delivery systems with emphasizes on liposomes, protein (specially human and bovine serum albumin)-based nanoparticles and polysaccharide (specially chitosan and dextran)-based nanoparticles as the biopolymeric nanoplatforms, which are decorated with mAbs, FA and Tf as the targeting ligands.