scholarly journals A virtual model of a vascularized bone matrix for biofabrication

Author(s):  
Maria Bolina Kersanach ◽  
Jorge Vicente Lopes da Silva ◽  
Janaina de Andrea Dernowsek

Increasingly, biofabrication is seen as a promising strategy in the tissue engineering and regenerative medicine fields. It proves to be a good alternative for drug and cosmetics testing and even for transplantation tissues and organs in humans. However, long before we dream with this science impacting our daily lives, we need to know it more on a smaller scale - the cellular interactions involved, the biomolecules, the transcription factors, the differentiation phases - it is all highly correlated, sensitive and complex. With the aim of reducing the investments of large sums of money and time with in vitro experiments, this work proposes the creation of a predictive model to the biological structures that will be biofabricated. From the use of mathematical and computational methods, simulations of biological phenomena are made through the translation of the biological processes described in the literature into logical processes written in programming languages. These in silico strategies make possible to iteratively refine physical and biochemical parameters before the in vitro stage. To exemplify this approach, an osteogenesis and angiogenesis implementation is shown in a virtual tissue spheroid (the bioprinting basic unit) - from mesenchymal and endothelial cells to a vascularized bone matrix.

Author(s):  
J. P. Revel

Movement of individual cells or of cell sheets and complex patterns of folding play a prominent role in the early developmental stages of the embryo. Our understanding of these processes is based on three- dimensional reconstructions laboriously prepared from serial sections, and from autoradiographic and other studies. Many concepts have also evolved from extrapolation of investigations of cell movement carried out in vitro. The scanning electron microscope now allows us to examine some of these events in situ. It is possible to prepare dissections of embryos and even of tissues of adult animals which reveal existing relationships between various structures more readily than used to be possible vithout an SEM.


Author(s):  
Bhikshapathi D. V. R. N. ◽  
Srinivas A

The main objective of this study was to develop fast dissolving oral films of ropinirole HCl to attain quick onset of action for the better management of Parkinson’s disease. Twenty-seven formulations (F1-F27) of ropinirole oral dissolving films by solvent-casting method using 33 response surface method by using HPMC E15, Maltodextrin PEG 4000 by using Design of experiment software. Formulations were evaluated for their physical characteristics, thickness, folding endurance, tensile strength, disintegration time, drug content uniformity and drug release characteristics and found to be within the limits. Among the prepared formulations F4 showed minimum disintegration time 11 sec, maximum drug was released i.e. 99.68 ± 1.52% of drug within 10 min when compared to the other formulations and finalized as optimized formulation. FTIR data revealed that no interactions takes place between the drug and polymers used in the optimized formulation. The in vitro dissolution profiles of marketed product and optimized formulation was compared and found to be the drug released was 92.77 ± 1.52 after 50 min. Therefore, it can be a good alternative to conventional ropinirole for immediate action. In vitro evaluation of the ropinirole fast dissolving films confirmed their potential as an innovative dosage form to improve delivery and quick onset of action of ropinirole. The oral dissolving film is considered to be potentially useful for the treatment of Parkinson’s disease where quick onset of action is desired


BIO-PROTOCOL ◽  
2014 ◽  
Vol 4 (4) ◽  
Author(s):  
Aurélie Tormo ◽  
Christian Beauséjour ◽  
Jean-François Gauchat
Keyword(s):  

Processes ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 45
Author(s):  
Ghmkin Hassan ◽  
Said M. Afify ◽  
Shiro Kitano ◽  
Akimasa Seno ◽  
Hiroko Ishii ◽  
...  

Defined by its potential for self-renewal, differentiation and tumorigenicity, cancer stem cells (CSCs) are considered responsible for drug resistance and relapse. To understand the behavior of CSC, the effects of the microenvironment in each tissue are a matter of great concerns for scientists in cancer biology. However, there are many complicated obstacles in the mimicking the microenvironment of CSCs even with current advanced technology. In this context, novel biomaterials have widely been assessed as in vitro platforms for their ability to mimic cancer microenvironment. These efforts should be successful to identify and characterize various CSCs specific in each type of cancer. Therefore, extracellular matrix scaffolds made of biomaterial will modulate the interactions and facilitate the investigation of CSC associated with biological phenomena simplifying the complexity of the microenvironment. In this review, we summarize latest advances in biomaterial scaffolds, which are exploited to mimic CSC microenvironment, and their chemical and biological requirements with discussion. The discussion includes the possible effects on both cells in tumors and microenvironment to propose what the critical factors are in controlling the CSC microenvironment focusing the future investigation. Our insights on their availability in drug screening will also follow the discussion.


Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 596
Author(s):  
Christian Jorgensen ◽  
Matthieu Simon

Joint-on-a-chip is a new technology able to replicate the joint functions into microscale systems close to pathophysiological conditions. Recent advances in 3D printing techniques allow the precise control of the architecture of the cellular compartments (including chondrocytes, stromal cells, osteocytes and synoviocytes). These tools integrate fluid circulation, the delivery of growth factors, physical stimulation including oxygen level, external pressure, and mobility. All of these structures must be able to mimic the specific functions of the diarthrodial joint: mobility, biomechanical aspects and cellular interactions. All the elements must be grouped together in space and reorganized in a manner close to the joint organ. This will allow the study of rheumatic disease physiopathology, the development of biomarkers and the screening of new drugs.


Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 397
Author(s):  
Gradimir Misevic ◽  
Emanuela Garbarino

Glycan-to-glycan binding was shown by biochemical and biophysical measurements to mediate xenogeneic self-recognition and adhesion in sponges, stage-specific cell compaction in mice embryos, and in vitro tumor cell adhesion in mammals. This intermolecular recognition process is accepted as the new paradigm accompanying high-affinity and low valent protein-to-protein and protein-to-glycan binding in cellular interactions. Glycan structures in sponges have novel species-specific sequences. Their common features are the large size >100 kD, polyvalency >100 repeats of the specific self-binding oligosaccharide, the presence of fucose, and sulfated and/or pyruvylated hexoses. These structural and functional properties, different from glycosaminoglycans, inspired their classification under the glyconectin name. The molecular mechanism underlying homophilic glyconectin-to-glyconectin binding relies on highly polyvalent, strong, and structure-specific interactions of small oligosaccharide motifs, possessing ultra-weak self-binding strength and affinity. Glyconectin localization at the glycocalyx outermost cell surface layer suggests their role in the initial recognition and adhesion event during the complex and multistep process. In mammals, Lex-to-Lex homophilic binding is structure-specific and has ultra-weak affinity. Cell adhesion is achieved through highly polyvalent interactions, enabled by clustering of small low valent structure in plasma membranes.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 861
Author(s):  
Jacopo Cardellini ◽  
Arianna Balestri ◽  
Costanza Montis ◽  
Debora Berti

In the past decade(s), fluorescence microscopy and laser scanning confocal microscopy (LSCM) have been widely employed to investigate biological and biomimetic systems for pharmaceutical applications, to determine the localization of drugs in tissues or entire organisms or the extent of their cellular uptake (in vitro). However, the diffraction limit of light, which limits the resolution to hundreds of nanometers, has for long time restricted the extent and quality of information and insight achievable through these techniques. The advent of super-resolution microscopic techniques, recognized with the 2014 Nobel prize in Chemistry, revolutionized the field thanks to the possibility to achieve nanometric resolution, i.e., the typical scale length of chemical and biological phenomena. Since then, fluorescence microscopy-related techniques have acquired renewed interest for the scientific community, both from the perspective of instrument/techniques development and from the perspective of the advanced scientific applications. In this contribution we will review the application of these techniques to the field of drug delivery, discussing how the latest advancements of static and dynamic methodologies have tremendously expanded the experimental opportunities for the characterization of drug delivery systems and for the understanding of their behaviour in biologically relevant environments.


2021 ◽  
Vol 11 (6) ◽  
pp. 2512
Author(s):  
Anca Labunet ◽  
Andreea Kui ◽  
Sorina Sava

Orthodontists must sometimes bond attachments to ceramic crowns, by using one of the surface preparations available, such as sandblasting or acid etching with hydrofluoric acid. Research shows that different laser systems may also be used for this purpose. The aim of this review is to determine which laser type and modality of use is the most effective in increasing shear bond strength of brackets bonded to ceramic surfaces. Two independent researchers studied the current literature 1990–2018 and selected original articles focusing on in vitro research on laser use for ceramic surface preparation for bonding metallic or ceramic attachments. Twelve articles have met the criteria and have been thoroughly revised, focusing on 2 fractional, Nd:Yag, Er:Yag, femtosecond and Ti:Sapphire lasers. There is little difference shown by the current studies between ceramic types and information on orthodontic bonding to non-feldspathic ceramics is scarce. Femtosecond laser is a good alternative to classical surface preparation with hydrofluoric acid. Nd:Yag laser is more suitable for surface preparation of ceramics than different types of Er:Yag lasers. Difference in laser power may achieve different results, but the golden standard for lasers use has not been found. Laser usage does not obtain the same results as hydrofluoric acid and cannot, so far, eliminate its application.


1962 ◽  
Vol 237 (11) ◽  
pp. 3555-3559
Author(s):  
William P. Deiss ◽  
Leila B. Holmes ◽  
C. Conrad Johnston
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document