Cas9 fusions for precision in vivo editing

2020 ◽  
Author(s):  
Ryan R. Richardson ◽  
Marilyn Steyert ◽  
Jeffrey Inen ◽  
Saovleak Khim ◽  
Andrea J. Romanowski ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Clonal Selection ◽  
High Specificity ◽  
Model Organisms ◽  
High Yield ◽  
Gene Therapies ◽  
Donor Template

AbstractCurrent Cas9 reagents can target genomic loci with high specificity. However, when used for knockin, on-target outcomes are inherently imprecise, often leading to unintended knockout rather than intended edits. This restricts applications of genome editing to ex vivo approaches, where clonal selection is possible. Here we describe a workflow using iterative high-throughput in vitro and high-yield in vivo assays to evaluate and compare the performance of CRISPR knockin reagents for both editing efficiency and precision. We tested combinations of Cas9 and DNA donor template variants and determined that Cas9-CtIP with in situ linearized donors display fold-increases of editing precision in cell lines and in vivo in the mouse brain. Iterating this process, we generated novel compound fusions, including eRad18-Cas9-CtIP that showed further fold-increases in performance. Continued development of precision editing reagents with this platform holds promise for direct in vivo knockin across model organisms and future targeted gene therapies.

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

scholarly journals EXTH-67. IDENTIFICATION AND DEVELOPMENT OF NEURAL ECM-BINDING LAMPREY ANTIBODIES (VARIABLE LYMPHOCYTE RECEPTORS) THAT TARGET GLIOBLASTOMA

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi96-vi96
Author(s):  
Benjamin Umlauf ◽  
Paul Clark ◽  
Jason Lajoie ◽  
Julia Georgieva ◽  
Samantha Bremner ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Ex Vivo ◽  
High Specificity ◽  
Recognition System ◽  
Brain Barrier ◽  
Disease Markers ◽  
Blood Brain ◽  
Lymphocyte Receptors

Abstract INTRODUCTION The median survival of glioblastoma (GBM) patients remains less than two years even with state-of-the-art treatment. Current targeted GBM therapies demonstrate initial therapeutic benefit; however, patients relapse due to therapeutic selection of treatment resistant GBM cellular populations. Therefore, we propose targeting pathologic disruption of the blood brain barrier (BBB) via exposure of neural ECM, rather than disease markers, to overcome therapy-resistant GBM. METHODS We identify Variable Lymphocyte Receptors (VLRs, the antigen recognition system used by lamprey) that demonstrate high specificity for neural ECM. Candidate VLRs underwent further refinement using in vitro binding assays and ex vivo tissue staining. Utilizing pathologic disruption of BBB as an approach for targeting GBM was confirmed in vivo using intracranial murine glioblastoma models. RESULTS The lead neural ECM-binding VLR candidate, named P1C10, demonstrates diffuse binding to parenchymal neural ECM, without detectable binding to other tissues. P1C10 demonstrates nanomolar affinity for in vitro derived neural ECM, and preferentially accumulates at intracranial GL261 and U87 lesions in murine GBM models. Finally, administration of P1C10-targeted doxorubicin-loaded liposomes significantly extends the survival of mice bearing intracranial U87 GBM. CONCLUSIONS We identified VLRs that bind neural ECM, and demonstrate their utility for delivering compounds and nanoparticles to sites of GBM induced blood brain barrier disruption. This novel strategy allows for targeting therapeutics via the underlying physiology of GBM rather than relying on cellular disease markers that are often lost in patients that relapse after targeting therapies.

scholarly journals Evaluation of persistence and fate of ex vivo edited-HSC modified with donor template and Its role in correcting Sickle Cell Disease

2021 ◽  
Author(s):  
Sowmya Pattabhi ◽  
Samantha N Lotti ◽  
Mason P Berger ◽  
David J Rawlings
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Ex Vivo ◽  
Cell Disease ◽  
Gene Correction ◽  
Healthy Human ◽  
Peripheral Blood Stem Cells ◽  
Donor Template

Sickle cell disease (SCD) is caused by a single nucleotide transversion in exon 1 of the HBB gene that changes the hydrophobicity of adult globin (βA), leading to substantial morbidity and reduced lifespan. Ex vivo autologous gene editing utilizing co-delivery of a designer nuclease along with a DNA donor template allows for precise homology-directed repair (HDR). These gene corrected cells when engrafted into the bone marrow (BM) can prove to be therapeutic and serves as an alternative to HLA-matched BM transplantation. In the current study, we extensively explored the role of single stranded oligonucleotide (ssODN) and recombinant adeno-associated 6 (rAAV6) donor template delivery to introduce a codon-optimized change (E6optE) or a sickle mutation (E6V) change following Crispr/Cas9-mediated cleavage of HBB in healthy human mobilized peripheral blood stem cells (mPBSCs). We achieved efficient HDR in vitro in edited cells and observed robust human CD45+ engraftment in the BM of NBSGW mice at 16-17 weeks. Notably, recipients of ssODN-modified HSC exhibited a significantly higher proportion of HDR-modified cells within individual BM, CD34+ and CD235+ compartments of both E6optE and E6V cohorts. We further assessed key functional outcomes including RNA transcripts analysis and globin sub-type expression. Our combined findings demonstrate the capacity to achieve clinically relevant HDR in vitro and in vivo using both donor template delivery method. The use of ssODN donor template-delivery is consistently associated with higher levels of gene correction in vivo as demonstrated by sustained engraftment of HDR-modified HSC and erythroid progeny. Finally, the HDR-based globin protein expression was significantly higher in the E6V ssODN-modified animals compared to the rAAV6-modified animals confirming that the ssODN donor template delivery outperforms rAAV6-donor template delivery.

In Situ Gels of Acylovir Nanoemulsions For Improved Delivery to The Eye

2021 ◽  
Vol 11 ◽  
Author(s):  
Manza M. Priyanka ◽  
Shinde A. Ujwala ◽  
Sheth M. Kalyani ◽  
Namita Desai
Keyword(s):  
Animal Studies ◽  
Ex Vivo ◽  
In Vitro Release ◽  
Corneal Stroma ◽  
Class Iii ◽  
Ophthalmic Delivery ◽  
Histopathological Studies

Background: Acyclovir, BCS Class III drug is commercially available as 3 % w/w eye ointment for multiple applications. Acyclovir nanoemulsions can be proposed to reduce dose because of improved permeation characteristics. Further, the development of in situ ophthalmic gels can be advantageous to reduce the number of applications due to increased mucoadhesion and sustaining effect. Objective: The purpose of this study was the development and evaluation of nanoemulsions based in situ gels of Acyclovir (1% w/w) as potential ophthalmic delivery systems. Methods: Nanoemulsions of Acyclovir were developed by Phase Inversion Temperature method using Capmul MCM, stearyl amine and Kolliphor RH 40 as liquid lipid, charge inducer and surfactant, respectively selected on the basis of Acyclovir solubility studies in the oil phase and emulsification ability of surfactants. These nanoemulsions were further developed into in situ ophthalmic gels using gellan gum and Methocel K4M. Results: The developed gels showed a sustained effect in vitro release studies and improved goat corneal permeation in ex vivo studies when compared to marketed ointment. HET-CAM studies concluded the absence of irritation potential, while in vivo irritation study in Wistar rats showed the absence of erythema and swelling of eyes after visual inspection for 72 hours. Histopathological studies on isolated rat corneas showed no abnormalities in anterior corneal epithelium and corneal stroma without any epithelial hyperplasia. Acyclovir nanoemulsions based in situ ophthalmic gel showed increased corneal deposition and permeation in rat eyes. Conclusion: The improved potential of developed ophthalmic gels was proven due to the reduced frequency of application compared to the marketed ointment in animal studies.

scholarly journals Opuntia dillenii (Ker Gawl.) Haw., Seeds Oil Antidiabetic Potential Using In Vivo, In Vitro, In Situ, and Ex Vivo Approaches to Reveal Its Underlying Mechanism of Action

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1677
Author(s):  
Mohamed Bouhrim ◽  
Hayat Ouassou ◽  
Salima Boutahiri ◽  
Nour Elhouda Daoudi ◽  
Hamza Mechchate ◽  
...  
Keyword(s):  
Mechanism Of Action ◽  
Ex Vivo ◽  
Ussing Chamber ◽  
Diabetic Rats ◽  
Postprandial Hyperglycemia ◽  
Antihyperglycemic Effect ◽  
Opuntia Dillenii

Opuntia dillenii Ker Gawl. is one of the medicinal plants used for the prevention and treatment of diabetes mellitus (DM) in Morocco. This study aims to investigate the antihyperglycemic effect of Opuntia dillenii seed oil (ODSO), its mechanism of action, and any hypoglycemic risk and toxic effects. The antihyperglycemic effect was assessed using the OGTT test in normal and streptozotocin (STZ)-diabetic rats. The mechanisms of action were explored by studying the effect of ODSO on the intestinal absorption of d-glucose using the intestinal in situ single-pass perfusion technique. An Ussing chamber was used to explore the effects of ODSO on intestinal sodium-glucose cotransporter 1 (SGLT1). Additionally, ODSO’s effect on carbohydrate degrading enzymes, pancreatic α-amylase, and intestinal α-glucosidase was evaluated in vitro and in vivo using STZ-diabetic rats. The acute toxicity test on mice was performed, along with a single-dose hypoglycemic effect test. The results showed that ODSO significantly attenuated the postprandial hyperglycemia in normal and STZ-diabetic rats. Indeed, ODSO significantly decreased the intestinal d-glucose absorption in situ. The ex vivo test (Ussing chamber) showed that the ODSO significantly blocks the SGLT1 (IC50 = 60.24 µg/mL). Moreover, ODSO indu\ced a significant inhibition of intestinal α-glucosidase (IC50 = 278 ± 0.01 µg/mL) and pancreatic α-amylase (IC50 = 0.81 ± 0.09 mg/mL) in vitro. A significant decrease of postprandial hyperglycemia was observed in sucrose/starch-loaded normal and STZ-diabetic ODSO-treated rats. On the other hand, ODSO had no risk of hypoglycemia on the basal glucose levels in normal rats. Therefore, no toxic effect was observed in ODSO-treated mice up to 7 mL/kg. The results of this study suggest that ODSO could be suitable as an antidiabetic functional food.

scholarly journals In Vitro or in Vivo Models, the Next Frontier for Unraveling Interactions between Malassezia spp. and Hosts. How Much do We Know?

2020 ◽  
Author(s):  
Maritza Torres ◽  
Hans De Cock ◽  
Adriana Marcela Celis Ramírez
Keyword(s):  
Galleria Mellonella ◽  
Fungal Infections ◽  
Ex Vivo ◽  
Model Organisms ◽  
In Vivo Models ◽  
Fungal Host ◽  
Alternative Models ◽  
Malassezia Spp

Malassezia is a lipid-dependent genus of yeasts known for being an important part of the skin mycobiota. These yeasts have been associated in the development of skin disorders and cataloged as a causal agent of systemic infections under specific conditions, making them opportunistic pathogens. Little is known about the host-microbe interaction of Malassezia spp., and unraveling this implies the implementation of infection models. In this mini review we present different models that have been implemented in the fungal infections study with greater attention in Malassezia spp. infections. These models range from in vitro (cell cultures and ex vivo tissue), to in vivo (murine models, rabbits, guinea pigs, insects, nematodes, and amoebas). We additionally highlight the alternative models that reduce the use of mammals as model organisms, which have been gaining importance in the study of fungal host-microbe interactions. This is due to the fact that these systems have shown to have reliable results, which correlate with those obtained from mammalian models. Example of alternative models are Caenorhabditis elegans, Drosophila melanogaster, Tenebrio molitor, and Galleria mellonella. These are invertebrates that have been implemented in the study of Malassezia spp. infections in order to identify differences in virulence between Malassezia species.

scholarly journals In Situ-Forming Cellulose/Albumin-Based Injectable Hydrogels for Localized Antitumor Therapy

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4221
Author(s):  
Ying Chen ◽  
Xiaomin Wang ◽  
Yudong Huang ◽  
Peipei Kuang ◽  
Yushu Wang ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Antitumor Therapy ◽  
Injectable Hydrogels ◽  
External Temperature ◽  
Minimal Invasiveness ◽  
In Situ Forming ◽  
External Stimuli

Injectable hydrogels, which are formed in situ by changing the external stimuli, have the unique characteristics of easy handling and minimal invasiveness, thus providing the advantage of bypass surgical operation and improving patient compliance. Using external temperature stimuli to realize the sol-to-gel transition when preparing injectable hydrogel is essential since the temperature is stable in vivo and controllable during ex vivo, although the hydrogels obtained possibly have low mechanical strength and stability. In this work, we designed an in situ fast-forming injectable cellulose/albumin-based hydrogel (HPC-g-AA/BSA hydrogels) that responded to body temperature and which was a well-stabilized hydrogen-bonding network, effectively solving the problem of poor mechanical properties. The application of localized delivery of chemotherapeutic drugs of HPC-g-AA/BSA hydrogels was evaluated. In vitro and in vivo results show that HPC-g-AA/BSA hydrogels exhibited higher antitumor efficacy of reducing tumor size and seem ideal for localized antitumor therapy.

Comparison of in-situ forming composite using PLGA-PEG-PLGA with in-situ forming implant using PLGA: In-vitro, ex-vivo, and in-vivo evaluation of naltrexone release

2019 ◽  
Vol 50 ◽  
pp. 188-200 ◽  
Author(s):  
Hossein Kamali ◽  
Elham Khodaverdi ◽  
Farzin Hadizadeh ◽  
Seyed Ahmad Mohajeri ◽  
Ali Nazari ◽  
...  
Keyword(s):  
Ex Vivo ◽  
In Vivo Evaluation ◽  
In Situ Forming
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