Circulating Tumor Cells in Cancer Diagnostics and Prognostics by Single-Molecule and Single-Cell Characterization

Circulating tumor cells (CTCs) represent an interesting source of biomarkers for diagnosis, prognosis, and the prediction of cancer recurrence, yet while they are extensively studied in oncobiology research, their diagnostic utility has not yet been demonstrated and validated. Their scarcity in human biological fluids impedes the identification of dangerous CTC subpopulations that may promote metastatic dissemination. In this Perspective, we discuss promising techniques that could be used for the identification of these metastatic cells. We first describe methods for isolating patient-derived CTCs and then the use of 3D biomimetic matrixes in their amplification and analysis, followed by methods for further CTC analyses at the single-cell and single-molecule levels. Finally, we discuss how the elucidation of mechanical and morphological properties using techniques such as atomic force microscopy and molecular biomarker identification using nanopore-based detection could be combined in the future to provide patients and their healthcare providers with a more accurate diagnosis.

Review on Porous Scaffolds Generation Process: A Tissue Engineering Approach

Porous scaffolds have been widely explored for tissue regeneration and engineering in vitro three-dimensional models. In this review, a comprehensive literature analysis is conducted to identify the steps involved in their generation. The advantages and disadvantages of the available techniques are discussed, highlighting the importance of considering pore geometrical parameters such as curvature and size, and summarizing the requirements to generate the porous scaffold according to the desired application. This paper considers the available design tools, mathematical models, materials, fabrication techniques, cell seeding methodologies, assessment methods, and the status of pore scaffolds in clinical applications. This review compiles the relevant research in the field in the past years. The trends, challenges, and future research directions are discussed in the search for the generation of a porous scaffold with improved mechanical and biological properties that can be reproducible, viable for long-term studies, and closer to being used in the clinical field.

The effects of process parameters on polydopamine coatings employed in tissue engineering applications

The biomaterials’ success within the tissue engineering field is hinged on the capability to regulate tissue and cell responses, comprising cellular adhesion, as well as repair and immune processes’ induction. In an attempt to enhance and fulfill these biomaterials’ functions, scholars have been inspired by nature; in this regard, surface modification via coating the biomaterials with polydopamine is one of the most successful inspirations endowing the biomaterials with surface adhesive properties. By employing this approach, favorable results have been achieved in various tissue engineering-related experiments, a significant one of which is the more rapid cellular growth observed on the polydopamine-coated substrates compared to the untreated ones; nonetheless, some considerations regarding polydopamine-coated surfaces should be taken into account to control the ultimate outcomes. In this mini-review, the importance of coatings in the tissue engineering field, the different types of surfaces requiring coatings, the significance of polydopamine coatings, critical factors affecting the result of the coating procedure, and recent investigations concerning applications of polydopamine-coated biomaterials in tissue engineering are thoroughly discussed.

Protein by-products: Composition, extraction, and biomedical applications

Significant upsurge in animal by-products such as skin, bones, wool, hides, feathers, and fats has become a global challenge and, if not properly disposed of, can spread contamination and viral diseases. Animal by-products are rich in proteins, which can be used as nutritional, pharmacologically functional ingredients, and biomedical materials. Therefore, recycling these abundant and renewable by-products and extracting high value-added components from them is a sustainable approach to reclaim animal by-products while addressing scarce landfill resources. This article appraises the most recent studies conducted in the last five years on animal-derived proteins' separation and biomedical application. The effort encompasses an introduction about the composition, an overview of the extraction and purification methods, and the broad range of biomedical applications of these ensuing proteins.

Effect of Olibanum Extract/Graphene Oxide on Differentiation of Bone Marrow Mesenchymal Stem Cells into Neuron-Like Cells on Freeze Dried Scaffolds

BACKGROUND

One of the challenges in using stem cells to neural repair is to induce their differentiation into neurons and lack of glial formation.

OBJECTIVES

Mesenchymal stem cells have revealed great potential for neural reorganization and renewal by taking advantage of differentiation capabilities. Here we explored the potential use of olibanum extract in freeze-dried scaffolds for induction of stem cells differentiation.

MATERIALS AND METHODS

In this study, gelatin/ collagen/olibanum/ graphene oxide (GEL/COL/OL/GO) freeze-dried scaffolds were synthesized and then adult rat bone marrow mesenchymal stem cells (BMMSCs) were seeded on scaffolds. The viability of cells was evaluated using MTT test on days 1, 3 and 5. The morphology of the cells seeded on scaffolds was studied using SEM and specific protein expression detected by immunohistochemical analysis. Real-time PCR was applied to detect the expression of Chat, Pax6, Hb-9, Nestin, Islet-1, and neurofilament-H (NF-H). The data were analyzed using Tukey test and one-way ANOVA and the means difference was considered significant at P<0.05, P<0.01, and P<0.001.

RESULTS

Showed that the pore size is increased in GEL/COL/OL/GO scaffolds compared with GO-free scaffolds and higher attachment and proliferation of BMMSCs on GEL/COL/OL /1.5% GO scaffolds compared to GEL/COL/OL/3% GO scaffolds. The cell viability results after 5 days of incubation showed the significant biocompatibility of GEL/COL/OL /1.5% GO freeze-dried scaffold. The results of immunohistochemical and PCR analysis revealed positive role of GEL/COL/OL/1.5% GO scaffolds in upregulation of neuron-specific markers.

CONCLUSION

These results reveal the great potential of GEL/COL/OL/GO scaffolds for nerve regeneration. Our data suggested that both OL extract and GO can regulate the MSCs differentiation into neurons.

Protein-Based Hydrogels: Promising Materials for Tissue Engineering

The successful design of a hydrogel for tissue engineering requires a profound understanding of its constituents' structural and molecular properties, as well as the proper selection of components. If the engineered processes are in line with the procedures that natural materials undergo to achieve the best network structure necessary for the formation of the hydrogel with desired properties, the failure rate of tissue engineering projects will be significantly reduced. In this review, we examine the behavior of proteins as an essential and effective component of hydrogels, and describe the factors that can enhance the protein-based hydrogels' structure. Furthermore, we outline the fabrication route of protein-based hydrogels from protein microstructure and the selection of appropriate materials according to recent research to growth factors, crucial members of the protein family, and their delivery approaches. Finally, the unmet needs and current challenges in developing the ideal biomaterials for protein-based hydrogels are discussed, and emerging strategies in this area are highlighted.

Biomaterials and strategies for repairing spinal cord lesions

Spinal cord injury (SCI) causes intractable disease and leads to inevitable physical, financial, and psychological burdens on patients and their families. SCI is commonly divided into primary and secondary injury. Primary injury occurs upon direct impact to the spinal cord, which leads to cell necrosis, axon disruption, and vascular loss. This triggers pathophysiological secondary injury, which has several phases: acute, subacute, intermediate, and chronic. These phases are dependent on post-injury time and pathophysiology and have various causes, such as the infiltration of inflammatory cells and release of cytokines that can act as a barrier to neural regeneration. Another unique feature of SCI is the glial scar produced from the reactive proliferation of astrocytes, which acts as a barrier to axonal regeneration. Interdisciplinary research is investigating the use of biomaterials and tissue-engineered fabrication to overcome SCI. In this review, we discuss representative biomaterials, including natural and synthetic polymers and nanomaterials. In addition, we describe several strategies to repair spinal cord injuries, such as fabrication and the delivery of therapeutic biocomponents. These biomaterials and strategies may offer beneficial information to enhance the repair of spinal cord lesions.

Effects of lamellar microstructure of retinoic acid loaded-matrixes on physicochemical properties, migration, and neural differentiation of P19 embryonic carcinoma cells

In this study, retinoic acid loaded-PLGA-gelatin matrixes were prepared with both freeze-casting and freeze-drying techniques. Herein, the effect of unidirectional microstructure with tunable pores on release profile, cellular adhesion, migration, and differentiation was compared. Morphological observation determined that highly interconnected porous structure can be formed, but lamellar pore channels were observed in freeze-casting prepared constructs. The absorption ratio was increased, and the biodegradation rate was decreased as a function of the orientation of microstructure. The in-vitro release study illustrated non-Fickian release mechanism in both methods, so that erosion has predominated over diffusion. Accordingly, PLGA-gelatin scaffolds prepared with freeze-drying technique showed no adequate erosion due to the rigid structure, while freeze-casting one presented more favorable erosion. Microscopic observations of adhered P19 embryonic cells on the scaffolds showed that the freeze-casting matrixes with unidirectional pores provide a more compatible microenvironment for cell attachments and spreading. Besides, it facilitated cell migration and penetration inside the structure and may act as guidance for neuron growth. Improvement in the expression of neural genes in unidirectionally oriented pores proved the decisive role of contact guidance for nerve healing. It seems that the freeze-cast PLGA-gelatin-retinoic acid scaffolds have initial features for nerve tissue regeneration studies.

Mussel-inspired polydopamine induced the osteoinductivity to ice-templating PLGA-gelatin matrix for bone tissue engineering application

In this study, poly(lactic-co-glycolic acid) (PLGA)-gelatin scaffolds were fabricated using the freeze-casting technique. Polydopamine (PDA) coating was applied on the surface of scaffolds to enhance the hydrophilicity, bioactivity, and cellular behavior of the composite constructs. Further, the synergistic effect of PDA coating and lamellar microstructure of scaffolds was evaluated on the promotion of properties. Based on morphological observations, freeze-casting constructs showed lamellar pore channels while the uniformity and pore size were slightly affected by deposition of PDA. The hydrophilicity and swelling capacity of the scaffolds were assessed using contact angle measurement and phosphate buffered saline absorption ratio. The results indicated a significant increment in water-matrix interactions following surface modification. The evaluation of the biodegradation ratio revealed the higher degree of degradation in PDA-coated samples owing to the presence of hydrophilic functional groups in the chemical structure of PDA. On the other hand, the bioactivity potential of PDA in the simulated body fluid solution confirmed the possibility of using coated constructs as a bone reconstructive substitute. The improvement of cellular attachment and filopodia formation in PDA-contained matrixes was the other benefit of the coating process. Furthermore, cellular proliferation and ALP activity were enhanced after PDA coating. The suggested PDA-coated PLGA-gelatin scaffolds can be applied in bone tissue regeneration.