Cytotoxicity of β-Cyclodextrins in Retinal Explants for Intravitreal Drug Formulations

Prajapati, Manisha; Christensen, Gustav; Paquet-Durand, François; Loftsson, Þorsteinn

doi:10.3390/molecules26051492

Cited by 9 publications

(5 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, this is not necessarily an effect of the formulation, since the control condition, where cell death is primarily caused by the explanation procedure, showed a similar trend. The observation that in murine explant cultures photoreceptors are more sensitive than second order neurons in the inner retina is consistent with previous data [ 30 , 42 ].…”

Section: Discussionsupporting

confidence: 93%

See 1 more Smart Citation

Investigating Ex Vivo Animal Models to Test the Performance of Intravitreal Liposomal Drug Delivery Systems

et al. 2021

Self Cite

View full text Add to dashboard Cite

There is a strong need for innovative and efficient drug delivery systems for ocular therapy development. However, testing intravitreal drug delivery systems without using live animals is challenging. Ex vivo animal models offer an interesting alternative. We analyzed the potential of using fresh porcine eyes obtained from the local slaughterhouse as a model for testing the intravitreal biodistribution and retention of liposomes with or without polyethylene glycol (PEG) conjugation and with different surface charges. The histology of the eyes was analyzed to localize the liposomes, and it was found that liposomes with PEG absorbed rapidly on the retina (within 1 h), with positively charged and PEG-coated liposomes being retained for at least 24 h. In parallel, fluorophotometry was employed on intact eyes, to determine the pharmacokinetics of the fluorophore calcein, as a substitute for a small hydrophilic therapeutic compound. We found a 4.5-fold increase in the vitreous half-life of calcein loaded in liposomes, compared with the free solution. Retinal toxicity was addressed using murine-derived retinal explant cultures. Liposomes were non-toxic up to 500 µg/mL. Toxicity was observed at 5 mg/mL for anionic and cationic liposomes, with 2-fold and 2.5-fold increased photoreceptor cell death, respectively. Overall, we could show that important ocular drug delivery considerations such as pharmacokinetics and biodistribution can be estimated in ex vivo porcine eyes, and may guide subsequent in vivo experiments.

show abstract

Section: Discussionsupporting

confidence: 93%

“…To detect dying cells in the retina cultures after addition of liposomes, a terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay was used. The protocol is available elsewhere [ 29 , 30 ]. The detection kit TMR red, Product No.…”

Section: Methodsmentioning

confidence: 99%

Investigating Ex Vivo Animal Models to Test the Performance of Intravitreal Liposomal Drug Delivery Systems

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

“…For mouse-derived retinas, the culture can be kept viable for up to 4 weeks (see above). The long-term viability of the retina also allows for the implementation of appropriate nanoparticle cytotoxicity studies ( Prajapati et al, 2021 ).…”

Section: Part 2: Studying Retinal Neuroprotection In Vitromentioning

confidence: 99%

In vitro Model Systems for Studies Into Retinal Neuroprotection

et al. 2022

Self Cite

View full text Add to dashboard Cite

Therapy development for neurodegenerative diseases of the retina constitutes a major unmet medical need, and this may be particularly relevant for inherited diseases of the retina, which are largely untreatable to this day. Therapy development necessitates appropriate models to improve the understanding of the underlying degenerative mechanisms, as well as for the testing and evaluation of novel treatment approaches. This review provides an overview of various in vitro model systems used to study retinal neuroprotection. The in vitro methods and technologies discussed range from primary retinal cell cultures and cell lines, to retinal organoids and organotypic retinal explants, to the cultivation of whole eyeballs. The advantages and disadvantages of these methods are compared and evaluated, also in view of the 3R principles (i.e., the refinement, reduction, and replacement of live animal testing), to identify suitable in vitro alternatives for in vivo experimentation. The article further expands on the use of in vitro models to test and evaluate neuroprotective treatments and to aid the development of retinal drug delivery systems. Among the pharmacological agents tested and characterized in vitro are such that interfere with aberrant cyclic guanosine monophosphate (cGMP) -signaling or such that inhibit the activities of poly (ADP-ribose) polymerase (PARP), histone deacetylases (HDAC), calpain-type proteases, as well as unfolded protein response-related stress. We then introduce nanoparticle-based drug delivery systems and discuss how different in vitro systems may be used to assess their efficacy in the treatment of retinal diseases. The summary provides a brief comparison of available in vitro models and relates their advantages and limitations to the various experimental requirements, for instance, for studies into disease mechanisms, novel treatments, or retinal toxicity. In many cases, combinations of different in vitro models may be required to obtain a comprehensive view of the efficacy of a given retinal neuroprotection approach.

show abstract

“…After fixation with 4 % paraformaldehyde, the histological work-up described above was followed to produce 14 µm thick sections. On the rd1 derived culture sections, a terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay was performed, detailed under a published protocol [22]. Mounting medium with DAPI was applied, and the sections imaged with fluorescent microscopy.…”

Section: Immunostaining Of Hek293t Cells and Murine Retinasmentioning

confidence: 99%

Pyruvate-conjugation of PEGylated liposomes effectively enhances their uptake in retinal photoreceptors

Christensen

Chen

Urimi

et al. 2022

Preprint

Self Cite

View full text Add to dashboard Cite

Despite several promising candidates there is a paucity of drug treatments available for patients suffering from retinal diseases. An important reason for this is the lack of suitable delivery systems that can achieve sufficiently high drug uptake in the retina and its photoreceptors. A promising and versatile method for drug delivery to specific cell types involves liposomes, surface-coated with substrates for transporter proteins highly expressed on the target cell. We identified strong lactate transporter (monocarboxylate transporter, MCT) expression on photoreceptors as a potential target for drug delivery vehicles. To evaluate MCT suitability for drug targeting, we used PEG-coated liposomes and conjugated these with different monocarboxylates, including lactate, pyruvate, and cysteine. Monocarboxylate-conjugated dye-loaded liposomes were tested on both human-derived cell-lines and murine retinal explant cultures. We found that liposomes conjugated with pyruvate consistently displayed higher cell uptake than unconjugated liposomes or liposomes conjugated with lactate or cysteine. Pharmacological inhibition of MCT1 and MCT2 reduced internalization, suggesting an MCT-mediated uptake mechanism. Pyruvate-conjugated liposomes loaded with the drug candidates CN03 and CN04 reduced photoreceptor cell death in murine rd1 and rd10 retinal degeneration models. Overall, this study proposes pyruvate-conjugated liposomes as a vehicle for drug delivery specifically to photoreceptors. Notably, in retinal degeneration models, free drug solutions could not achieve the same therapeutic effect. Our study thus highlights pyruvate-conjugated liposomes as a promising system for drug delivery to retinal photoreceptors, as well as other neuronal cell types displaying high expression of MCT-type proteins.

show abstract

Cytotoxicity of β-Cyclodextrins in Retinal Explants for Intravitreal Drug Formulations

Cited by 9 publications

References 57 publications

Investigating Ex Vivo Animal Models to Test the Performance of Intravitreal Liposomal Drug Delivery Systems

Investigating Ex Vivo Animal Models to Test the Performance of Intravitreal Liposomal Drug Delivery Systems

In vitro Model Systems for Studies Into Retinal Neuroprotection

Pyruvate-conjugation of PEGylated liposomes effectively enhances their uptake in retinal photoreceptors

Contact Info

Product

Resources

About