Strategies to Maximize the Potential of Marine Biomaterials as a Platform for Cell Therapy

Marine Macroalgal Polygalactan-Built Nanoparticle Construct for Osteogenesis

Naturally derived polysaccharide biopolymer-based nanoparticles with their size and drug release potentials have appeared as promising biomaterials for osteogenic differentiation. A metallic nanoparticle (GS-AgNP) prepared from a sulfated polygalactan characterized as →3)-2-O-methyl-O-6-sulfonato-β-d-galactopyranosyl-(1 → 4)-2-O-methyl-3,6-anhydro-α-d-galactopyranose-(1→ isolated from the marine macroalga Gracilaria salicornia exhibited a prospective osteogenic effect. Upon treatment with the studied GS-AgNP, alkaline phosphatase activity (88.9 mU/mg) was significantly elevated in human mesenchymal osteoblast stem cells (hMSCs) compared to that in the normal control (33.7 mU/mg). A mineralization study of GS-AgNPs demonstrated an intense mineralized nodule formation on the hMSC surface. A fluorescence-activated cell sorting study of osteocalcin and bone morphogenic protein-2 (BMP-2) expression resulted in an increased population of osteocalcin (78.64%) and BMP-2-positive cells (46.10%) after treatment with GS-AgNPs (250 μg/mL) on M2 macrophages. A time-dependent cell viability study of GS-AgNPs exhibited its non-cytotoxic nature. The studied polygalactan-built nanoparticle could be developed as a promising bioactive pharmacophore against metabolic bone disorder and the treatment for osteogenesis therapy.

Free Marine Natural Products Databases for Biotechnology and Bioengineering

Marine organisms and micro-organisms are a source of natural compounds with unique chemical features. These chemical properties are useful for the discovery of new functions and applications of marine natural products (MNPs). To extensively exploit the potential implementations of MNPs, they are gathered in chemical databases that allow their study and screening for applications of biotechnological interest. However, the classification of MNPs is currently poor in generic chemical databases. The present availability of free-access-focused MNP databases is scarce and the molecular diversity of these databases is still very low when compared to the paid-access ones. In this review paper, the current scenario of free-access MNP databases is presented as well as the hindrances involved in their development, mainly compound dereplication. Examples and opportunities for using freely accessible MNP databases in several important areas of biotechnology are also assessed. The scope of this paper is, as well, to notify the latent potential of these information sources for the discovery and development of new MNPs in biotechnology, and push future efforts to develop a public domain MNP database freely available for the scientific community.

A straightforward method for quantification of vinyl functionalized water soluble alginates via 13C-NMR spectroscopy

Alginates are fairly abundant in nature and possess many interesting properties, including their biocompatibility and ability to absorb large amounts of water. Hence, increasing interest in their derivatization has been observed and the determination of the number of newly introduced functionalities has become a key issue. For this purpose, literature generally reports on conventional ¹H-NMR spectra, typically recorded at elevated temperatures and/or after hydrolysis of the alginate to circumvent line broadening effects resulting from the high viscosity. The present work reports on the modification of alginate with methacrylate functionalities and determination of the resulting degree of substitution (DS), i.e. the number of introduced methacrylate moieties relative to the initial amount of hydroxyl groups along the alginate backbone, via NMR spectroscopy. Freeze-drying and low power water presaturation were applied to improve the quality of the ¹H NMR spectra. Nevertheless, it remains a qualitative method, to be used only for mutual comparisons of samples. A new and accurate method for DS determination of methacrylated alginates, based on ¹³C-NMR spectroscopy, is proposed. Quantitative ¹³C-NMR spectra were recorded with reduced measuring times by addition of a paramagnetic relaxation agent. The proposed method will also be applicable for other water-soluble functionalized alginates and polysaccharides in general.

Drug loaded microbeads entrapped electrospun mat for wound dressing application

A new design of antibiotic loaded wound dressing and its initial in vitro evaluation is described. Chitosan microbeads loaded with ampicillin were sandwiched within polycaprolactone electrospun mat (MbAPPCL). The morphology was analyzed by scanning electron microscopy and surface chemistry was characterized by Fourier Transform Infrared Spectroscopy. In vitro cytotoxicity using L-929 fibroblast cells by direct contact test and elution assay revealed non-cytotoxic nature of MbAPPCL. The cell adhesion and viability analysis further confirmed the cytocompatibility of MbAPPCL as a wound dressing material. Percentage hemolysis and platelet adhesion on the mat exposed to blood substantiated the hemocompatibility. The antibiotic susceptibility test analyzed on Staphylococcus aureus by agar plate method confirmed the drug release and antimicrobial property. The proposed wound dressing model explained with ampicillin as a candidate drug has the potential to include microbeads with different antibiotics for multi drug treatment.