Trajectory-Based Tissue Engineering for Cartilage Repair: Correlation Between Maturation Rate and Integration Capacity

2013 ◽  
Author(s):  
Matthew B. Fisher ◽  
Nicole Söegaard ◽  
David R. Steinberg ◽  
Robert L. Mauck
Keyword(s):  
Tissue Engineering ◽  
Time Course ◽  
Biomechanical Properties ◽  
Time Dependent ◽  
In Vivo Studies ◽  
Surgical Approaches ◽  
General Hypothesis ◽  
Vitro Assay

Given the limitations of current surgical approaches to treat articular cartilage injuries, tissue engineering (TE) approaches have been aggressively pursued over the past two decades. Although biochemical and biomechanical properties on the order of the native tissue have been achieved (1–5), several in-vitro and in-vivo studies indicate that increased tissue maturity may limit the ability of engineered constructs to remodel and integrate with surrounding cartilage, although results are highly variable (2, 6–8). Thus, “static” measures of construct maturity (e.g. compressive modulus) upon implantation may not be the best indicators of in-vivo success, which likely requires implanted TE constructs to mature, remodel, and integrate with the host over time to achieve optimal results. We recently introduced the concept of “trajectory-based” tissue engineering (TB-TE), which is based on the general hypothesis that time-dependent increases in construct maturation in-vitro prior to implantation (i.e. positive rates) may provide a better predictor of in-vivo success (9). As a first step in evaluating this concept, in the current study we hypothesized that time-dependent increases in equilibrium modulus (a metric of growth) would be correlated to ability of constructs to integrate to cartilage using an in-vitro assay. To test this hypothesis, the current objective was to determine and model the time course of maturation of TE constructs during in-vitro culture and to assess the ability of these constructs to integrate to cartilage at various points during their maturation.

scholarly journals Regenerative medicine for skeletal muscle loss: a review of current tissue engineering approaches

2021 ◽  
Vol 32 (1) ◽  
Author(s):  
Benjamin Langridge ◽  
Michelle Griffin ◽  
Peter E. Butler
Keyword(s):  
Skeletal Muscle ◽  
Tissue Engineering ◽  
Three Dimensional ◽  
In Vivo Studies ◽  
Current Status ◽  
Surgical Approaches ◽  
Muscle Loss ◽  
Functional Maturation

AbstractSkeletal muscle is capable of regeneration following minor damage, more significant volumetric muscle loss (VML) however results in permanent functional impairment. Current multimodal treatment methodologies yield variable functional recovery, with reconstructive surgical approaches restricted by limited donor tissue and significant donor morbidity. Tissue-engineered skeletal muscle constructs promise the potential to revolutionise the treatment of VML through the regeneration of functional skeletal muscle. Herein, we review the current status of tissue engineering approaches to VML; firstly the design of biocompatible tissue scaffolds, including recent developments with electroconductive materials. Secondly, we review the progenitor cell populations used to seed scaffolds and their relative merits. Thirdly we review in vitro methods of scaffold functional maturation including the use of three-dimensional bioprinting and bioreactors. Finally, we discuss the technical, regulatory and ethical barriers to clinical translation of this technology. Despite significant advances in areas, such as electroactive scaffolds and three-dimensional bioprinting, along with several promising in vivo studies, there remain multiple technical hurdles before translation into clinically impactful therapies can be achieved. Novel strategies for graft vascularisation, and in vitro functional maturation will be of particular importance in order to develop tissue-engineered constructs capable of significant clinical impact.

TRENDS AND CHALLENGES OF CARTILAGE TISSUE ENGINEERING

2009 ◽  
Vol 21 (03) ◽  
pp. 149-155 ◽  
Author(s):  
Hsu-Wei Fang
Keyword(s):  
Tissue Engineering ◽  
Stem Cells ◽  
Growth Factors ◽  
Bone Cells ◽  
Cartilage Tissue Engineering ◽  
Bioactive Molecules ◽  
In Vivo Studies ◽  
Cartilage Tissue

Cartilage injuries may be caused by trauma, biomechanical imbalance, or degenerative changes of joint. Unfortunately, cartilage has limited capability to spontaneous repair once damaged and may lead to progressive damage and degeneration. Cartilage tissue-engineering techniques have emerged as the potential clinical strategies. An ideal tissue-engineering approach to cartilage repair should offer good integration into both the host cartilage and the subchondral bone. Cells, scaffolds, and growth factors make up the tissue engineering triad. One of the major challenges for cartilage tissue engineering is cell source and cell numbers. Due to the limitations of proliferation for mature chondrocytes, current studies have alternated to use stem cells as a potential source. In the recent years, a lot of novel biomaterials has been continuously developed and investigated in various in vitro and in vivo studies for cartilage tissue engineering. Moreover, stimulatory factors such as bioactive molecules have been explored to induce or enhance cartilage formation. Growth factors and other additives could be added into culture media in vitro, transferred into cells, or incorporated into scaffolds for in vivo delivery to promote cellular differentiation and tissue regeneration.Based on the current development of cartilage tissue engineering, there exist challenges to overcome. How to manipulate the interactions between cells, scaffold, and signals to achieve the moderation of implanted composite differentiate into moderate stem cells to differentiate into hyaline cartilage to perform the optimum physiological and biomechanical functions without negative side effects remains the target to pursue.

scholarly journals Tissue Engineering of Muscles and Cartilages Using Polyelectrolyte Hydrogels

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Hyuck Joon Kwon
Keyword(s):  
Tissue Engineering ◽  
In Vivo Studies ◽  
Current Status ◽  
Polyelectrolyte Gel ◽  
Polyelectrolyte Gels ◽  
Joint Surfaces ◽  
Functional Replacement ◽  
And Cartilage

The prevalent nature of osteoarthritis that causes the erosion of joint surfaces and loss of mobility and muscle dystrophy that weakens the musculoskeletal system and hampers locomotion underlies the importance of developing functional replacement or regeneration of muscle and cartilage tissues. Polyelectrolyte gels have high potential as cellular scaffolds due to characteristic properties similar to biological matrixes. A number of in vitro and in vivo studies demonstrated that polyelectrolyte gels are useful for replacement and regeneration of muscle and cartilage tissues. In addition, it was also found that polyelectrolyte gels have high biocompatibility, durability, and resistance to biodegradation. Moreover, polyelectrolyte gels can overcome their drawbacks of mechanical behavior by introducing double network into the gel. This paper reviews the current status and recent progress of polyelectrolyte gel-based tissue engineering for repairs of muscle and cartilage tissues.

scholarly journals A new in vitro assay for carbon dioxide excretion by trout red blood cells: effects of catecholamines

1991 ◽  
Vol 157 (1) ◽  
pp. 349-366 ◽  
Author(s):  
C. M. Wood ◽  
S. F. Perry
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
Time Course ◽  
In Vitro Assay ◽  
Vitro Assay ◽  
Acid Base Status ◽  
Excretion Rates ◽  
Co2 Excretion

A new in vitro assay was developed and critically characterized to measure the rate of CO2 excretion by trout red blood cells (RBCs) from HCO3- in their natural plasma under normal in vivo conditions of acid-base status. The assay is based on the addition of [14C]bicarbonate to the whole blood and collection of the resultant 14CO2 in the overlying gas phase. The assay simulates the exposure of blood passing through the gills, and measured CO2 excretion rates are representative of those occurring in vivo. Rates are linear over the 3 min time course of the assay, related to haematocrit in a non-linear fashion, elevated by the addition of carbonic anhydrase, reduced by blockade with acetazolamide, and sensitive to variations of equilibration PCO2. Large variations in plasma [HCO3-] have only a small effect on CO2 excretion rates when the blood is chronically equilibrated at these levels. Acute elevations in [HCO3-], however, create a non-equilibrium situation, resulting in large increases in CO2 excretion. When the blood is acidified, to duplicate typical post-exercise metabolic acidosis, adrenaline causes a marked inhibition of RBC CO2 excretion. The response is transient, reaching a peak 5–8 min after addition of adrenaline and disappearing by 30–60 min. The magnitude of the adrenergic inhibition is correlated with the magnitude of the RBC pHi regulatory response, expressed as the RBC transmembrane pH difference (pHe-pHi). These results support the ‘CO2 retention theory’ explaining observed increases in blood PCO2 in vivo after exhaustive exercise and catecholamine infusions in fish.

The Fibrinolytic Potential of the Normal Primate following the Generation of Thrombin In Vivo

1990 ◽  
Vol 63 (03) ◽  
pp. 476-481 ◽  
Author(s):  
Alan R Giles ◽  
Michael E Nesheim ◽  
Steven W Herring ◽  
Hugh Hoogendoorn ◽  
David C Stump ◽  
...  
Keyword(s):  
Time Course ◽  
Factor Xa ◽  
Lipid Vesicles ◽  
Experimental Period ◽  
In Vivo Studies ◽  
Full Time ◽  
Primate Model ◽  
Fibrinolytic Potential

SummaryParameters of the fibrinolytic system were studied in a primate model where the generation of thrombin was promoted in vivo. The procoagulant stimulus used was a combination of human factor Xa in combination with phosphatidylcholine/phos-phatidylserine lipid vesicles (PCPS) as the source of coagulant active phospholipid. The dosage of each component was formulated to provide a gradation of thrombin generating potential assessed prior to in vivo study in an in vitro clotting assay. These ranged from 25.25 - 36.60 pMole/kg (factor Xa) and 18.85 - 56.30 nMole/kg (PCPS). In each case, the ratio of the dose of factor Xa/PCPS was maintained at 0.65 (pMole factor Xa/ nMole PCPS). Individual dosage combinations producing recalcification clotting times in vitro of 15, 20, 25 and 30 s were used in detailed in vivo studies. Previous studies in dogs had confirmed the thrombin generating potential of factor Xa/PCPS infusions and demonstrated an associated activation ot protein C and increased fibrinolytic activity. This has now been extensively characterized in the chimpanzee as follows: 10 min after the infusion of the highest dose (36.6 pMole factor Xa/56.3 nMole PCPS kg bodyweight), the level of circulating t-PA had risen to 900 ng/ml (antigen), 885 IU/ml (functional). Dosage was observed with the lowest dose of 12.25 pMole factor Xa and 18.85 nMole PCPS being associated with relatively minor increases in circulating t-PA activity. There were no changes in u-PA at any dosage during the full time course of the experimental period (90 min). Plasminogen activation was also apparent with alpha-2 antiplasmin levels falling to 30 - 40% of pre-infusion levels at the highest dosages. There was also a significant consumption of fibrinogen and evidence of active fibrinolysis manifested by major increases in the levels of FDP, D-dimer and B-beta 1-42. The data strongly suggested that this was predominantly fibrinolysis rather than fibrinogenolysis and that the fibrinolytic response observed resulted from a major release of t-PA from available stores consequent to thrombin generation and presumably subsequent fibrin generation. These data illustrate the enormous fibrinolytic potential of the intact normal primate and may provide a model for study of the mechanism(s) by which the regulation of t-PA availability can be up- or down-regulated in health and disease.

scholarly journals Detoxification of Implant Surfaces Affected by Peri-Implant Disease: An Overview of Surgical Methods

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Pilar Valderrama ◽  
Thomas G. Wilson Jr
Keyword(s):  
In Vivo Studies ◽  
Surgical Approaches ◽  
Validity And Reliability ◽  
Implant Surface ◽  
Advantages And Disadvantages ◽  
Surgical Methods ◽  
Term Evaluation

Purpose. Peri-implantitis is one of the major causes of implant failure. The detoxification of the implant surface is necessary to obtain reosseointegration. The aim of this review was to summarize in vitro and in vivo studies as well as clinical trials that have evaluated surgical approaches for detoxification of the implant body surfaces.Materials and Methods. A literature search was conducted using MEDLINE (PubMed) from 1966 to 2013. The outcome variables were the ability of the therapeutic method to eliminate the biofilm and endotoxins from the implant surface, the changes in clinical parameters, radiographic bone fill, and histological reosseointegration.Results. From 574 articles found, 76 were analyzed. The findings, advantages, and disadvantages of using mechanical, chemical methods and lasers are discussed.Conclusions. Complete elimination of the biofilms is difficult to achieve. All therapies induce changes of the chemical and physical properties of the implant surface. Partial reosseointegration after detoxification has been reported in animals. Combination protocols for surgical treatment of peri-implantitis in humans have shown some positive clinical and radiographic results, but long-term evaluation to evaluate the validity and reliability of the techniques is needed.

Tissue engineering auricular reconstruction: in vitro and in vivo studies

Biomaterials ◽  
2004 ◽  
Vol 25 (9) ◽  
pp. 1545-1557 ◽  
Author(s):  
Shyh-Jou Shieh ◽  
Shinichi Terada ◽  
Joseph P Vacanti
Keyword(s):  
Tissue Engineering ◽  
In Vivo Studies ◽  
Auricular Reconstruction

scholarly journals Improvements in HOMA indices and pancreatic endocrinal tissues in type 2-diabetic rats by DPP-4 inhibition and antioxidant potential of an ethanol fruit extract of Withania coagulans

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Heera Ram ◽  
Pramod Kumar ◽  
Ashok Purohit ◽  
Priya Kashyap ◽  
Suresh Kumar ◽  
...  
Keyword(s):  
Diabetic Rats ◽  
In Vivo Studies ◽  
Model Assessment ◽  
Fruit Extract ◽  
Vitro Assay ◽  
Withania Coagulans ◽  
Type 2 Diabetic

Abstract Context Withania coagulans (Stocks) Dunal fruits are used in the therapeutics of several ailments due to possessing of potent phytoconstituents which is also used traditionally for curing the diabetes. Objective The present study was assessing the amelioration potential of the phytochemicals of an ethanol fruit extract of W. coagulans (Stocks) Dunal in the HOMA (Homeostatic model assessment) indices and pancreatic endocrinal tissues by inhibition of DPP-4 and antioxidants activities. Material and methods The identification of phytoconstituents of the test extract was performed by LCMS. Further, assessments of in-vitro, in-vivo and in-silico were achieved by following standard methods. In-vivo studies were conducted on type-2 diabetic rats. Results The chosen extract inhibited DPP-4 activity by 63.2% in an in vitro assay as well as significantly inhibit serum DPP-4 levels. Accordingly, the administration of the ethanol fruit extract resulted in a significant (P ≤ 0.001) alterations in the lipid profile, antioxidant levels, and HOMA indices. Moreover, pancreatic endocrinal tissues (islet of Langerhans) appeared to have the restoration of normal histoarchitecture as evidenced by increased cellular mass. Molecular docking (Protein-ligands) of identified phytoconstituents with DPP-4 (target enzyme) shown incredibly low binding energy (Kcal/mol) as required for ideal interactions. ADMET analysis of the pharmacokinetics of the identified phytoconstituents indicated an ideal profile as per Lipinski laws. Conclusion It can be concluded that the phytoconstituents of an ethanol fruit extract of W. coagulans have the potential to inhibit DPP-4 which result in improved glucose homeostasis and restoration of pancreatic endocrinal tissues in type-2 diabetic rats.

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