Collagen and the Effect of Poly-L-lactic Acid based Materials on its Synthesis

2021 ◽  
Author(s):  
Subarna Ray ◽  
Hossein Adelnia ◽  
Hang Thu Ta
Keyword(s):  
Lactic Acid ◽  
Structural Stability ◽  
Biological Functions ◽  
Connective Tissues ◽  
Important Protein

Collagen is an important protein in various biological functions such as providing elasticity and waterproofing to the skin, structural stability to the cells in connective tissues (e.g. tendons, and bone)...

Structural Changes in Pericardium Tissue Modified with Tannic Acid

2005 ◽  
Vol 28 (6) ◽  
pp. 648-653 ◽  
Author(s):  
B. Cwalina ◽  
A. Turek ◽  
J. Nozynski ◽  
M. Jastrzebska ◽  
Z. Nawrat
Keyword(s):  
Structural Stability ◽  
Tannic Acid ◽  
Structural Changes ◽  
Enzymatic Digestion ◽  
Connective Tissues ◽  
Tissue Resistance ◽  
Sds Page ◽  
Microscopic Studies ◽  
Morphological Differences ◽  
Porcine Pericardium

Introduction Structural modification of proteins, mainly collagen in connective tissues, is important in the manufacture of tissue-derived biomaterials. Natural compounds like genipin or tannic acid (TA) have been proposed instead of glutaraldehyde which shows cytotoxic effects on the processed tissue. Furthermore, calcification of glutaraldehyde-treated tissue limits the functional lifetime of bioprostheses. TA is known to form numerous hydrogen bonds with proteins. The purpose of our study was to investigate structural changes in porcine pericardium upon chemical modification with tannic acid. Methods Porcine pericardium tissue (PP) was soaked in 2% TA for 4, 24 or 48 hours. Changes in tissue structure were studied using electrophoresis (SDS-PAGE) and histological examination. Structural stability of PP tissue was evaluated by SDS/NaCl extraction method and enzymatic digestion with pancreatin. Results TA-modification of PP caused a time-dependent decrease in the number of peptides extracted from tissue. Microscopic studies revealed no significant morphological differences between native and TA-modified tissues, except for the native pancreatin-digested tissue where lack of both cells and low molecular peptides was observed. Conclusion Modification of PP with TA causes the structural changes leading to an increase in the tissue resistance to SDS/NaCl extraction and enzymatic digestion, providing experimental evidence for the higher structural stability of TA-treated tissue.

scholarly journals EGR1 Transcription Factor is a Multifaceted Regulator of Matrix Production in Tendons and Other Connective Tissues

2020 ◽  
Vol 21 (5) ◽  
pp. 1664 ◽  
Author(s):  
Emmanuelle Havis ◽  
Delphine Duprez
Keyword(s):  
Extracellular Matrix ◽  
Transcription Factor ◽  
Connective Tissue ◽  
Transcriptional Activity ◽  
Tendon Repair ◽  
Regulatory Elements ◽  
Biological Functions ◽  
Connective Tissues ◽  
Post Translational Modifications ◽  
Matrix Production

Although the transcription factor EGR1 is known as NGF1-A, TIS8, Krox24, zif/268, and ZENK, it still has many fewer names than biological functions. A broad range of signals induce Egr1 gene expression via numerous regulatory elements identified in the Egr1 promoter. EGR1 is also the target of multiple post-translational modifications, which modulate EGR1 transcriptional activity. Despite the myriad regulators of Egr1 transcription and translation, and the numerous biological functions identified for EGR1, the literature reveals a recurring theme of EGR1 transcriptional activity in connective tissues, regulating genes related to the extracellular matrix. Egr1 is expressed in different connective tissues, such as tendon (a dense connective tissue), cartilage and bone (supportive connective tissues), and adipose tissue (a loose connective tissue). Egr1 is involved in the development, homeostasis, and healing processes of these tissues, mainly via the regulation of extracellular matrix. In addition, Egr1 is often involved in the abnormal production of extracellular matrix in fibrotic conditions, and Egr1 deletion is seen as a target for therapeutic strategies to fight fibrotic conditions. This generic EGR1 function in matrix regulation has little-explored implications but is potentially important for tendon repair.

scholarly journals Maintaining Structural Stability of Poly(lactic acid): Effects of Multifunctional Epoxy based Reactive Oligomers

Polymers ◽  
2014 ◽  
Vol 6 (4) ◽  
pp. 1232-1250 ◽  
Author(s):  
Sahas Rathi ◽  
Edward Coughlin ◽  
Shaw Hsu ◽  
Charles Golub ◽  
Gerald Ling ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Structural Stability ◽  
Poly Lactic Acid

Thermoresponsive elastin/laminin mimicking artificial protein for modifying PLLA scaffolds in nerve regeneration

2014 ◽  
Vol 2 (31) ◽  
pp. 5061-5067 ◽  
Author(s):  
Sachiro Kakinoki ◽  
Tetsuji Yamaoka
Keyword(s):  
Lactic Acid ◽  
Nerve Regeneration ◽  
Biological Functions ◽  
Artificial Protein

Poly(l-lactic acid) (PLLA) is widely used as a scaffold but does not possess biological functions.

scholarly journals Hyaluronic acid (hyaluronan): a review

2008 ◽  
Vol 53 (No. 8) ◽  
pp. 397-411 ◽  
Author(s):  
J. Necas ◽  
L. Bartosikova ◽  
P. Brauner ◽  
J. Kolar
Keyword(s):  
Hyaluronic Acid ◽  
Integral Membrane Proteins ◽  
Pharmacological Properties ◽  
Clinical Use ◽  
Biological Functions ◽  
Connective Tissues ◽  
Vitreous Fluid ◽  
Hyaluronan Synthases ◽  
Naturally Occurring ◽  
Umbilical Cords

Hyaluronic acid (HA) is a high molecular weight biopolysacharide, discovered in 1934, by Karl Meyer and his assistant, John Palmer in the vitreous of bovine eyes. Hyaluronic acid is a naturally occurring biopolymer, which has important biological functions in bacteria and higher animals including humans. It is found in most connective tissues and is particularly concentrated in synovial fluid, the vitreous fluid of the eye, umbilical cords and chicken combs. It is naturally synthesized by a class of integral membrane proteins called hyaluronan synthases, and degraded by a family of enzymes called hyaluronidases. This review describes metabolisms, different physiological and pathological functions, basic pharmacological properties, and the clinical use of hyaluronic acid.

scholarly journals Antimicrobial activity of Ocimum gratissimum extract on suya (an intermediate moisture meat) in Nigeria

2014 ◽  
Vol 14 (66) ◽  
pp. 9361-9375
Author(s):  
OO Olusola ◽  
◽  
OS Oyadeyi ◽  
AB Omojola ◽  
TS Olugbemi ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Biochemical Characterization ◽  
Bacterial Count ◽  
Lactobacillus Species ◽  
Connective Tissues ◽  
Ocimum Gratissimum ◽  
Tb Treatment ◽  
Randomized Design

Matured leaves of Ocimum gratissimum were harvested and the extracts used to cure Suya (an intermediate moisture meat). O. gratissimum leaves were collected from Oyo state south west region of Nigeria, rinsed in distilled water and squeezed to extract the fluid. The meat used was Semi membranosus muscle from beef carcass, which was trimmed of all visible fat and connective tissues. The meat cut was sliced into sheets of 0.18cm-0.35cm thick and lengths of between 5.0cm-7.1cm. The study comprised five treatments with 10 replicates each in a completely randomized design. Treatment A (TA) served as the control (Suya without O. gratissimum extract(OGE), while treatment B (TB),treatment C (TC), treatment D (TD) and treatment E (TE) were Suya soaked in OGE for ½ hr, 1hr, l½ hrs and 2 hrs, respectively, before coating with Suya ingredients. A total of 50 sticks of Suya weighing from 38.10 - 59.30 grams of sliced meat per stick were prepared for each treatment. The meat on sticks was properly coated with Suya ingredients and arranged around glowing embers of charcoal. The morphological and biochemical characterization of aerobic bacteria, coliform and lactic acid isolates from the five treatments was carried out. At Day 0, isolates from samples of the five treatments include: Aerobic species of Pseudomonas, Bacillus, Micrococcus, and Flavobacterium species. Three Coliform species isolated were: Proteus, Aeromonas and Enterobacter species. The four Lactic acid bacteria isolated were Pediococcus, Streptococcus, Lactobacillus species and Enterococcus feacalis. The bacterial count on Suya meat soaked in OGE at different curing times of ½ hr, 1hr, 1½ hrs and 2hrs differed. The aerobic counts (0.001x105-2.2x105) were relatively low at the third and fifth days for TC, TD, and TE while for Lactic acid bacteria, the count reduced from 3.0x105 in TA to 0.2x105 in TE. Coliform counts of 6.0x105 and 7.0x105 recorded at day 7 for TA and TB were exceptionally high. O. gratissimum extract, used as a curing agent in suya production significantly reduced the aerobic count of treated meat, thus enhancing the keeping quality of the products.

Bioengineered human blood vessels

Science ◽  
2020 ◽  
Vol 370 (6513) ◽  
pp. eaaw8682 ◽  
Author(s):  
Laura E. Niklason ◽  
Jeffrey H. Lawson
Keyword(s):  
Blood Vessels ◽  
Cell Biology ◽  
Coagulation System ◽  
Early 20Th Century ◽  
Biological Functions ◽  
Connective Tissues ◽  
The Past ◽  
Artificial Materials ◽  
Acute Injuries ◽  
Human Arteries

Since the advent of the vascular anastomosis by Alexis Carrel in the early 20th century, the repair and replacement of blood vessels have been key to treating acute injuries, as well as chronic atherosclerotic disease. Arteries serve diverse mechanical and biological functions, such as conducting blood to tissues, interacting with the coagulation system, and modulating resistance to blood flow. Early approaches for arterial replacement used artificial materials, which were supplanted by polymer fabrics in recent decades. With recent advances in the engineering of connective tissues, including arteries, we are on the cusp of seeing engineered human arteries become mainstays of surgical therapy for vascular disease. Progress in our understanding of physiology, cell biology, and biomanufacturing over the past several decades has made these advances possible.

Structural stability of photodegradable poly(l-lactic acid)/PE/TiO2 nanocomposites through TiO2 nanospheres and TiO2 nanotubes incorporation

2014 ◽  
Vol 71 (5) ◽  
pp. 1205-1217 ◽  
Author(s):  
Kacris Idianês Matos da Silva ◽  
Jesum Alves Fernandes ◽  
Emerson Cristofer Kohlrausch ◽  
Jairton Dupont ◽  
Marcos José Leite Santos ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Structural Stability ◽  
Tio2 Nanotubes

scholarly journals Genetic engineering of mesenchymal stromal cells for cancer therapy: turning partners in crime into Trojan horses

2016 ◽  
Vol 1 (1) ◽  
pp. 19-32 ◽  
Author(s):  
Hanno Niess ◽  
Michael N. Thomas ◽  
Tobias S. Schiergens ◽  
Axel Kleespies ◽  
Karl-Walter Jauch ◽  
...  
Keyword(s):  
Mesenchymal Stromal Cells ◽  
Stromal Cells ◽  
Current Knowledge ◽  
Cell Types ◽  
The Body ◽  
Biological Functions ◽  
Connective Tissues ◽  
Differentiation Potential ◽  
Underlying Mechanisms ◽  
Do So

AbstractMesenchymal stromal cells (MSCs) are adult progenitor cells with a high migratory and differentiation potential, which influence a broad range of biological functions in almost every tissue of the body. Among other mechanisms, MSCs do so by the secretion of molecular cues, differentiation toward more specialized cell types, or influence on the immune system. Expanding tumors also depend on the contribution of MSCs to building a supporting stroma, but the effects of MSCs appear to go beyond the mere supply of connective tissues. MSCs show targeted “homing” toward growing tumors, which is then followed by exerting direct and indirect effects on cancer cells. Several research groups have developed novel strategies that make use of the tumor tropism of MSCs by engineering them to express a transgene that enables an attack on cancer growth. This review aims to familiarize the reader with the current knowledge about MSC biology, the existing evidence for MSC contribution to tumor growth with its underlying mechanisms, and the strategies that have been developed using MSCs to deploy an anticancer therapy.

scholarly journals Antimicrobial activity of Ocimum gratissimum extract on suya (an intermediate moisture meat) in Nigeria

2014 ◽  
Vol 14 (66) ◽  
pp. 9361-9375
Author(s):  
OO Olusola ◽  
◽  
OS Oyadeyi ◽  
AB Omojola ◽  
TS Olugbemi ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Biochemical Characterization ◽  
Bacterial Count ◽  
Lactobacillus Species ◽  
Connective Tissues ◽  
Ocimum Gratissimum ◽  
Tb Treatment ◽  
Randomized Design

Matured leaves of Ocimum gratissimum were harvested and the extracts used to cure Suya (an intermediate moisture meat). O. gratissimum leaves were collected from Oyo state south west region of Nigeria, rinsed in distilled water and squeezed to extract the fluid. The meat used was Semi membranosus muscle from beef carcass, which was trimmed of all visible fat and connective tissues. The meat cut was sliced into sheets of 0.18cm-0.35cm thick and lengths of between 5.0cm-7.1cm. The study comprised five treatments with 10 replicates each in a completely randomized design. Treatment A (TA) served as the control (Suya without O. gratissimum extract(OGE), while treatment B (TB),treatment C (TC), treatment D (TD) and treatment E (TE) were Suya soaked in OGE for ½ hr, 1hr, l½ hrs and 2 hrs, respectively, before coating with Suya ingredients. A total of 50 sticks of Suya weighing from 38.10 - 59.30 grams of sliced meat per stick were prepared for each treatment. The meat on sticks was properly coated with Suya ingredients and arranged around glowing embers of charcoal. The morphological and biochemical characterization of aerobic bacteria, coliform and lactic acid isolates from the five treatments was carried out. At Day 0, isolates from samples of the five treatments include: Aerobic species of Pseudomonas, Bacillus, Micrococcus, and Flavobacterium species. Three Coliform species isolated were: Proteus, Aeromonas and Enterobacter species. The four Lactic acid bacteria isolated were Pediococcus, Streptococcus, Lactobacillus species and Enterococcus feacalis. The bacterial count on Suya meat soaked in OGE at different curing times of ½ hr, 1hr, 1½ hrs and 2hrs differed. The aerobic counts (0.001x105-2.2x105) were relatively low at the third and fifth days for TC, TD, and TE while for Lactic acid bacteria, the count reduced from 3.0x105 in TA to 0.2x105 in TE. Coliform counts of 6.0x105 and 7.0x105 recorded at day 7 for TA and TB were exceptionally high. O. gratissimum extract, used as a curing agent in suya production significantly reduced the aerobic count of treated meat, thus enhancing the keeping quality of the products.

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