Current Pharmaceutical Biotechnology - Volume 17, Issue 5, 2016

The field of medicine is rapidly moving towards the development of personalized treatments and non-invasive tools to achieve a more predictable and optimal tissue regeneration. In this sense, the goal of periodontal healing is to arrest disease progression and functionally regenerate all the tissues that comprise the periodontium. The latter implies a well-orchestrated interaction among oral cells, growth factors and extracellular matrix. Although several procedures are performed in an attempt to regenerate lost periodontal tissue, outcomes are not always predictable. Growth factors represent a class of biologically active polypeptides that have a critical role in the healing process. Their use provides a new paradigm to understand the regenerative medicine. The use of platelet- rich plasma (PRP) products as a local source and delivery system of autologous growth factors has emerged recently. Among them, PRGF stands for its remarkable stimulatory effect on oral tissue regeneration, making it a very safe and successful tool with a great value in Dentistry.

The Toll-like family of immune receptors (TLRs) are critical for an efficient immune response to a variety of microorganisms and other antigens that may cause pathology. Modulating immune responses by targeting TLRs therefore has substantial therapeutic potential, and a number of TLR-based therapeutic strategies have been developed. Minimizing the adverse effects that may result from the therapeutic manipulation of these signalling receptors nevertheless remains a major challenge. Efficient responses via TLRs require the activity of the co-receptor CD14, which enhances TLR responses. In an attempt to boost the immune response for therapeutic purposes, we have sought to target CD14 to achieve TLR modulation. Here we discuss the design, activity and therapeutic development options of TLR-derived peptides that interact with CD14 and enhance its co-receptor activity, thus amplifying TLR-mediated responses. This strategy represents a promising alternative to current TLR-based therapies, as it has the potential to amplify responses to different pathogens mediated by different TLRs by targeting the common TLR co-receptor, CD14.

Healing process might be considered as a byproduct of the mechanisms underlying the biological defense system consisting of hemostasis and clotting, the innate immune system, and fibrogenesis. But there is no biological process that does not potentially entail high costs through trade-offs with other life-history parameters and that might be seen as collateral damage. Depending on the balance among the robust and flexible modular defense system, which will be deployed in many different arrays, the structural outcome of the healing process will not resolve with a unitary outcome. Drawing on the regenerative potential of platelets, plasma biomolecules and fibrin matrix, several systems of producing autologous platelets-and plasma derived products (APPDPs) have been developed and aimed at enhancing the natural in vivo tissue regenerative capacity of damaged tissues. Despite the care with which the medical staff elaborate and apply autologous platelets-and plasma derived products, some pitfalls arise regarding the composition of autologous plasma-and platelet derived products, the modalities of their application, and the in vitro versus in vivo evaluations, all of which can deeply influence tissue healing – a process which is already unpredictable, without a unitary mechanism that might be deployed in many different structural and functional arrays which culminate in the tissue repair. A biological approach to the application of autologous platelets-and plasma derived products is crucial to obtaining optimum functional healing outcomes in addition to avoiding poor clinical results and reaching misleading conclusions.

In Biotechnology, the expression of recombinant proteins is a constantly growing field and different hosts are used for this purpose. Some valuable proteins cannot be produced using traditional systems. Insects from the order Lepidoptera infected with recombinant baculovirus have appeared as a good choice to express high levels of proteins, especially those with post-translational modifications. Lepidopteran insects, which are extensively distributed in the world, can be used as small protein factories, the new biofactories. Species like Bombyx mori (silkworm) have been analyzed in Asian countries to produce a great number of recombinant proteins for use in basic and applied science and industry. Many proteins expressed in this larva have been commercialized. Several recombinant proteins produced in silkworms have already been commercialized. On the other hand, species like Spodoptera frugiperda, Heliothis virescens, Rachiplusia nu, Helicoverpa zea and Trichoplusia ni are widely distributed in both the occidental world and Europe. The expression of recombinant proteins in larvae has the advantage of its low cost in comparison with insect cell cultures. A wide variety of recombinant proteins, including enzymes, hormones and vaccines, have been efficiently expressed with intact biological activity. The expression of pharmaceutically proteins, using insect larvae or cocoons, has become very attractive. This review describes the use of insect larvae as an alternative to produce commercial recombinant proteins.

We present a brief survey of some of the recent work of Professor Luis E. Díaz, performed together with his students and collaborators at the University of Buenos Aires. Dr Luis E. Díaz has been involved in research on biochemical and pharmaceutical sciences solving scientific and industry problems for over 40 years until he passed away. Prof. Díaz scientific interests included various topics from NMR spectroscopy to biomedicine but fundamentally he focused in various aspects of chemistry (analytical, organic, inorganic and environmental). This is not a complete survey but a sampling of prominent projects related to sol-gel chemistry with a focus on some of his recent publications.

Solid phase screenings of one bead one compound (OBOC) libraries have been widely used to find ligands with pharmacological and analytical uses, and to purify or detect proteins in complex mixtures. To improve library screening, in the last years various strategies have been developed to avoid the selection of false positive beads and to obtain selective ligands. Currently, there is great interest in cyclic peptides because of their resistance to enzymatic degradation and higher selectivity compared to their linear counterparts. Lots of cyclic peptide libraries protocols have been recently developed to facilitate hits analysis. The aim of this review is to summarize the latest applications of solid phase screening of OBOC combinatorial peptide libraries, the improvements in the screening methods including mass spectrometry MS/MS techniques and the strategies to synthesize OBOC cyclic peptide libraries.

The design and development of novel biological drugs are among the most exciting new areas of biotechnology which are gaining the attention of scientists. In the last few decades several fabrication processes have been proposed and developed for the production of recombinant growth factors. However, traditional production processes have several limitations in terms of scale- up, cost-efficiency and purity grade of the proteins. In the present study, we propose for the first time the proof-of-concept of large-scale production of growth factors in plants as a new alternative to other production processes. We have decided to select vascular endothelial growth factor (VEGF) as model assuming its key role in cell survival and regenerative medicine. Results show that the present protocol is efficient to scale up a purification procedure of rh VEGF isoform 165 in Nicotiana benthamiana plants. Our procedure resulted in dimeric VEGF protein with high purity degree and yield, which showed full biological activity over endothelial and epithelial cells, suggesting great potential for its use in regenerative medicine. This protein could be exploited not only in tissue repair and regeneration but also as a biologically active ingredient in dermocosmetics.

The application of silica nanoparticles (NPs) in the biomedical field experienced a great development. The driving forces for these and future developments are the possibility to design NPs with homogeneous size and structure amenable to specific grafting. Moreover, it is possible to tune the characteristics of the NPs to meet the requirements of each specific cell and desired application. Herein, we analyzed the effect of silica NPs of various sizes and surface charge on the viability of Spodoptera frugiperda cells (Sf9 cell line) with the aim of extending the knowledge of possible toxicity of the NPs in the environment and development of new tools for insect control. Moreover, these results will also contribute to develop more effective systems for gene vectors delivery and recombinant proteins expression. Bare silica NPs of 14 nm, 380 nm and 1430 nm as well as amine-modified silica NPs of 131 nm and 448 nm were obtained by the Stöber method. The NPs were characterized by DLS and zeta potential measurements. The cell viability was assessed by the MTT test. It was observed that the 14 nm NPs possess the highest toxic effect. Indeed, after 24h, the viability of the cells exposed to the lower concentration of NPs (0.12 mg/ml) was about 40% of the value obtained for the control cells not exposed to NPs. Moreover, the exposure to other negative charged NPs also causes a lower activity when compared with the control. Alternatively, lower concentrations of positive charged NPs (i.e.: 0.12 or 0.6 mg/ml) demonstrated to stimulate the proliferation of the cells and higher concentrations (i.e.: 7.2 mg/ml) did not present significant differences with the control. In conclusion, we have demonstrated that the NPs possess an effect that is highly influenced by the size, charge and concentration. Although, silica NPs are being used in the biomedical field, these results contribute to further understanding the risk that could be associated to nanoparticles and how these can be modified in order to meet the requirements of each desired application.

A clear link exists between the extension of life expectancy throughout the world and the increased incidence of age-related neurodegenerative disorders. Diseases like Alzheimer’s and Parkinson’s are chronic diseases with devastating consequences for patients and their families. They also represent a major economic cost for society. Therapeutic progress has been made mainly by alleviating some of the symptoms of these diseases, but currently no cure is available. Attempts to develop new therapies have been hampered mainly because of gaps in our current knowledge about the pathogenic mechanism underlying neurodegeneration, making difficult the identification of targets for new drug development, and also because of the lack of biomarkers essential for early diagnosis, patient stratification and follow up of treatment. Taking advantage of the latest technical developments, proteomics and peptidomics based approaches are being used to identify new cellular pathophysiological pathways as well as biomarkers in biological fluids. Here we will review the results, mainly published in the last five years, of unbiased proteomics and peptidomics approaches for biomarker research using biological fluids of Alzheimer’s, Parkinson’s and Amyotrophic Lateral Sclerosis patients.