scholarly journals Generation of vascular chimerism within donor organs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shahar Cohen ◽  
Shirly Partouche ◽  
Michael Gurevich ◽  
Vladimir Tennak ◽  
Vadym Mezhybovsky ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Patient Specific ◽  
Machine Perfusion ◽  
Organ Perfusion ◽  
Perfusion Process ◽  
Hind Limbs ◽  
Porcine Organs ◽  
Immunological Barrier

AbstractWhole organ perfusion decellularization has been proposed as a promising method to generate non-immunogenic organs from allogeneic and xenogeneic donors. However, the ability to recellularize organ scaffolds with multiple patient-specific cells in a spatially controlled manner remains challenging. Here, we propose that replacing donor endothelial cells alone, while keeping the rest of the organ viable and functional, is more technically feasible, and may offer a significant shortcut in the efforts to engineer transplantable organs. Vascular decellularization was achieved ex vivo, under controlled machine perfusion conditions, in various rat and porcine organs, including the kidneys, liver, lungs, heart, aorta, hind limbs, and pancreas. In addition, vascular decellularization of selected organs was performed in situ, within the donor body, achieving better control over the perfusion process. Human placenta-derived endothelial progenitor cells (EPCs) were used as immunologically-acceptable human cells to repopulate the luminal surface of de-endothelialized aorta (in vitro), kidneys, lungs and hind limbs (ex vivo). This study provides evidence that artificially generating vascular chimerism is feasible and could potentially pave the way for crossing the immunological barrier to xenotransplantation, as well as reducing the immunological burden of allogeneic grafts.

scholarly journals In situ genetic engineering of tumors for long-lasting and systemic immunotherapy

2020 ◽  
Vol 117 (8) ◽  
pp. 4043-4052 ◽  
Author(s):  
Stephany Y. Tzeng ◽  
Kisha K. Patel ◽  
David R. Wilson ◽  
Randall A. Meyer ◽  
Kelly R. Rhodes ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Cellular Therapy ◽  
Ex Vivo ◽  
A Priori ◽  
Costimulatory Molecule ◽  
Patient Specific ◽  
A Priori Knowledge ◽  
Priori Knowledge

Cancer immunotherapy has been the subject of extensive research, but highly effective and broadly applicable methods remain elusive. Moreover, a general approach to engender endogenous patient-specific cellular therapy, without the need for a priori knowledge of tumor antigen, ex vivo cellular manipulation, or cellular manufacture, could dramatically reduce costs and broaden accessibility. Here, we describe a biotechnology based on synthetic, biodegradable nanoparticles that can genetically reprogram cancer cells and their microenvironment in situ so that the cancer cells can act as tumor-associated antigen-presenting cells (tAPCs) by inducing coexpression of a costimulatory molecule (4-1BBL) and immunostimulatory cytokine (IL-12). In B16-F10 melanoma and MC38 colorectal carcinoma mouse models, reprogramming nanoparticles in combination with checkpoint blockade significantly reduced tumor growth over time and, in some cases, cleared the tumor, leading to long-term survivors that were then resistant to the formation of new tumors upon rechallenge at a distant site. In vitro and in vivo analyses confirmed that locally delivered tAPC-reprogramming nanoparticles led to a significant cell-mediated cytotoxic immune response with systemic effects. The systemic tumor-specific and cell-mediated immunotherapy response was achieved without requiring a priori knowledge of tumor-expressed antigens and reflects the translational potential of this nanomedicine.

In-vitro, ex-vivo, and in-vivo release evaluation of in situ forming buprenorphine implants using mixture of PLGA copolymers and additives

2018 ◽  
Vol 68 (16) ◽  
pp. 965-977 ◽  
Author(s):  
Hossein Kamali ◽  
Elham Khodaverdi ◽  
Farzin Hadizadeh ◽  
Seyed Ahmad Mohajeri ◽  
Younes Kamali ◽  
...  
Keyword(s):  
Ex Vivo ◽  
In Situ Forming ◽  
In Vivo Release

DEVELOPMENT AND EVALUATION OF NANOPARTICULATE BASED IN-SITU GELLING SYSTEM FOR NASAL DRUG DELIVERY OF AN ANTI-EPILEPTIC DRUG

INDIAN DRUGS ◽  
2017 ◽  
Vol 54 (09) ◽  
pp. 83-85
Author(s):  
A Ambavkar ◽  
◽  
N. Desai
Keyword(s):  
Drug Release ◽  
Ex Vivo ◽  
Entrapment Efficiency ◽  
Poloxamer 407 ◽  
Nasal Drug Delivery ◽  
Anti Epileptic Drug ◽  
Nanolipid Carriers ◽  
In Situ Nasal Gel

The objective of the study was to develop and evaluate nanolipid carriers based in situ gel of Carbamazepine, for brain delivery through intranasal route. The non – invasive nasal route can provide rapid delivery of drugs directly to the central nervous system by bypassing the blood brain barrier. The nanolipid carriers of carbamazepine as in situ nasal gel can prolong the drug release for control of repetitive seizures and were prepared by Phase Inversion Temperature technique. The retention of the carriers in the nasal cavity was improved by using Poloxamer 407 as thermoresponsive and Carbopol 974P as mucoadhesive gelling polymers, respectively. The developed gel was evaluated for particle size, polydispersity index, zeta potential, morphology, entrapment efficiency, mucoadhesive and thermoresponsive behaviour, in vitro drug release, ex vivo permeation and nasociliotoxicity. The gel showed sustained release over prolonged periods and was found to be non-toxic to the sheep nasal mucosa.

Preparation of levofloxacin loaded in situ gel for sustained ocular delivery: in vitro and ex vivo evaluations

2019 ◽  
Vol 46 (1) ◽  
pp. 50-56 ◽  
Author(s):  
Pooja Jain ◽  
Chandra Prakash Jaiswal ◽  
Mohd. Aamir Mirza ◽  
Md. Khalid Anwer ◽  
Zeenat Iqbal
Keyword(s):  
Ex Vivo ◽  
Ocular Delivery ◽  
In Situ Gel

scholarly journals Biomechanical simulations and 3D printing for endovascular device testing

2020 ◽  
Author(s):  
Michele Conti ◽  
Stefania Marconi ◽  
Ferdinando Auricchio
Keyword(s):  
3D Printing ◽  
Mechanical Response ◽  
Ex Vivo ◽  
Invasive Procedure ◽  
Patient Specific ◽  
Human Aorta ◽  
In Vitro Tests ◽  
Aortic Diseases ◽  
Endovascular Device

Endovascular aortic repair is a minimally invasive procedure to treat aortic diseases such as aneurysms and dissections. Thanks to technological advancements, such procedure has steadily shifted from the abdominal aorta towards the ascending part, i.e., near the heart, calling for an extensive and comprehensive benchmarking of (novel) endografts. Given such considerations, we have exploited porcine aorta with a pulse duplicator to analyse the mechanical interaction between the endovascular device and the native tissue. Our results have implications for using the porcine aorta as a model for human aorta in research. Particularly, the combination of in vitro tests performed using ex-vivo tissue, integrated validated patient-specific numerical simulations, mock arteries manufactured by 3D printing, can offer important insight on biomechanical impact of endograft design on post-operative aortic mechanical response.

scholarly journals DEVELOPMENT AND EVALUATION OF A POLOXAMER- AND CHITOSAN-BASED IN SITU GEL-FORMING INJECTABLE DEPOT

2020 ◽  
pp. 36-41
Author(s):  
Hema a Nair ◽  
NAZIA BEGUM
Keyword(s):  
Ex Vivo ◽  
Gelation Time ◽  
In Vitro Release ◽  
Aqueous Acetic Acid ◽  
Drug Content ◽  
Low Viscosity ◽  
Model Drug ◽  
Dialysis Bag

Objective: The present study is intended to investigate the applicability of poloxamer- and chitosan-based temperature induced in situ injectable gelling depot for once a week therapy as an intramuscular injection employing olanzapine as a model drug. Methods: The thermosetting gel was prepared by admixture of a solution of poloxamer P127 and a solution of olanzapine and chitosan in aqueous acetic acid. The resultant formulation was characterized for gelation temperature, gelation time, viscosity, syringeability, pH, drug content, and in vitro drug release. The in vitro release of olanzapine from the gelled depot was followed using USP paddle type II apparatus in conjunction with a dialysis bag. The gel was injected ex vivo into chicken muscle and observed by subsequent dissection. Results: The formulation was designed to have a phase transition temperature of 34°C and gelled in <10 s at 37°C. Addition of chitosan imparted favorable rheological properties to the poloxamer gel and resulted in a pseudoplastic mixture with low viscosity in the sol state and higher viscosity post gelation. The preparation had a pH of 5.4, appropriate drug content and readily passed through a 20 gauge needle. The release of olanzapine was unhindered by the dialysis bag. Following an initial bust, a sustained, zero-order release of the remainder of drug was observed up to 9 days. The injectable was found to form a compact depot when evaluated ex vivo. Conclusion: The developed system showed several features which make it a suitable vehicle for sustained intramuscular delivery of drugs.

scholarly journals Measurement and analysis of sarcomere length in rat cardiomyocytes in situ and in vitro

2010 ◽  
Vol 298 (5) ◽  
pp. H1616-H1625 ◽  
Author(s):  
G. Bub ◽  
P. Camelliti ◽  
C. Bollensdorff ◽  
D. J. Stuckey ◽  
G. Picton ◽  
...  
Keyword(s):  
Measurement Errors ◽  
Sarcomere Length ◽  
Ex Vivo ◽  
Living Cells ◽  
Perfused Heart ◽  
Experimental Conditions ◽  
Rat Cardiomyocytes ◽  
Two Photon

Sarcomere length (SL) is an important determinant and indicator of cardiac mechanical function; however, techniques for measuring SL in living, intact tissue are limited. Here, we present a technique that uses two-photon microscopy to directly image striations of living cells in cardioplegic conditions, both in situ (Langendorff-perfused rat hearts and ventricular tissue slices, stained with the fluorescent marker di-4-ANEPPS) and in vitro (acutely isolated rat ventricular myocytes). Software was developed to extract SL from two-photon fluorescence image sets while accounting for measurement errors associated with motion artifact in raster-scanned images and uncertainty of the cell angle relative to the imaging plane. Monte-Carlo simulations were used to guide analysis of SL measurements by determining error bounds as a function of measurement path length. The mode of the distribution of SL measurements in resting Langendorff-perfused heart is 1.95 μm ( n = 167 measurements from N = 11 hearts) after correction for tissue orientation, which was significantly greater than that in isolated cells (1.71 μm, n = 346, N = 9 isolations) or ventricular slice preparations (1.79 μm, n = 79, N = 3 hearts) under our experimental conditions. Furthermore, we find that edema in arrested Langendorff-perfused heart is associated with a mean SL increase; this occurs as a function of time ex vivo and correlates with tissue volume changes determined by magnetic resonance imaging. Our results highlight that the proposed method can be used to monitor SL in living cells and that different experimental models from the same species may display significantly different SL values under otherwise comparable conditions, which has implications for experiment design, as well as comparison and interpretation of data.

In vitro and ex vivo characterisation of an in situ gelling formulation for sustained lidocaine release with potential use following knee arthroplasty

2018 ◽  
Vol 8 (3) ◽  
pp. 820-829 ◽  
Author(s):  
Manisha Sharma ◽  
Kaushik Chandramouli ◽  
Louise Curley ◽  
Beau Pontre ◽  
Keryn Reilly ◽  
...  
Keyword(s):  
Knee Arthroplasty ◽  
Ex Vivo ◽  
In Situ Gelling ◽  
Potential Use

scholarly journals Development and Correlation between in vitro Drug Release and in vitro Permeation of Thermally Triggered Mucoadhesive in situ Nasal Gel of Repaglinide PVP K30 Complex

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Kamla Pathak ◽  
Anil Kumar ◽  
Ekta Yadav
Keyword(s):  
Ex Vivo ◽  
Solid Dispersions ◽  
In Vitro Release ◽  
Type Ii Diabetes Mellitus ◽  
Poloxamer 407 ◽  
Ex Vivo Permeation ◽  
In Situ Nasal Gel ◽  
Pvp K30

The aim of the investigation was to develop and evaluate thermoreversible in situ nasal gel formulations of repaglinide (REP) and to establish correlation between its in vitro release and ex vivo permeation profiles. The solubility of REP was enhanced by preparing solid dispersions (SDs) with hydrophilic carriers (PVP K30/ PEG 6000/ poloxamer 188) in different weight ratios. REP: PVP K30 (1:5) was selected as the optimized SD as it showed highest enhancement in solubility (405%). The optimized SD was characterized by SEM and DSC and incorporated into a blend of thermoreversible and mucoadhesive polymers (poloxamer 407 and carbopol 934 P) by cold technique to form in situ gels (F1-F6). The prepared in-situ gels were evaluated for various pharmacotechnical features and the formulation F3 exhibited least gelling time of 6.1± 0.20, good mucoadhesive property to ensure sufficient residence time at the site of application and a %CDR of 82.25%. The ex vivo permeation characteristics across goat mucosa can be summarized as CDP of 78.7%, flux = 6.80 mg/cm2/h; permeability coefficient of 2.02 mg/h and zero order kinetics. On correlating the CDR profile of F3 with that of its CDP profile, a R2 value of 0.991 (slope= 0.921) was observed. The value of slope approximating one, suggested that almost entire amount of drug released from F3 was capable of permeating across the nasal mucosa, ex-vivo indicating that in-situ nasal gels of REP for systemic action can be successfully developed for the management non-insulin dependent type-II diabetes mellitus.

scholarly journals Preservation of Mitochondrial Coupling and Renal Function by Controlled Oxygenated Rewarming of Porcine Kidney Grafts

Biomolecules ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1880
Author(s):  
Hristo Zlatev ◽  
Charlotte von Horn ◽  
Thomas Minor
Keyword(s):  
Cold Storage ◽  
Negative Impact ◽  
Ex Vivo ◽  
Coupling Efficiency ◽  
Sodium Reabsorption ◽  
Enzyme Release ◽  
Machine Perfusion ◽  
Early Functional Outcome ◽  
Perfusion Period

Background: Warm reperfusion after previous cold storage has been shown to have a negative impact on mitochondrial function of organ grafts. Here, we wanted to investigate whether a more controlled warming up of the cold graft by ex vivo machine perfusion with gradually elevated temperature from cold to normothermia (including comparison of two warming up protocols) prior to implantation would be effective in preventing mitochondrial dysfunction upon reperfusion. Methods: All experiments were conducted on porcine kidneys retrieved 15 min after cardiac arrest. After 18 h of cold storage in HTK solution (CS, n = 6), kidneys (n = 6) were subjected to 2 h of reconditioning machine perfusion starting with a hypothermic period followed by a gradual increase in perfusion temperature up to 35 °C (controlled oxygenated rewarming—COR). For a second group (n = 6), the slow warming up was begun instantly after connecting the graft onto the machine (iCOR). Functional recovery of all grafts was then observed upon normothermic reperfusion in vitro. At the conclusion of the experiments, tissue specimens were taken for immediate isolation and analysis of renal mitochondria. Results: COR resulted in a significantly and more than 3-fold increased glomerular filtration rate upon reperfusion, along with a significant higher tubular sodium reabsorption and lesser loss of glucose in comparison to the controls. Enzyme release (AST) was also massively reduced during the reperfusion period. Specific analysis at the mitochondrial level revealed significantly better coupling efficiency and spare respiratory capacity in the COR group compared to the cold storage group. Interestingly, additional experiments revealed that the omission of a hypothermic perfusion period did not deteriorate any of the results after COR, provided that the instant temperature increase from 10 to 35 °C was effectuated in the same controlled manner. Conclusion: Controlled rewarming after extended cold preservation effectively improves mitochondrial recovery upon reperfusion and early functional outcome of kidney grafts.

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