Transplantation into the Anterior Chamber of the Eye for Longitudinal, Non-invasive In vivo Imaging with Single-cell Resolution in Real-time
March 10th, 2013
A new approach combining intraocular transplantation and confocal microscopy enables longitudinal, non-invasive real-time imaging with single-cell resolution within grafted tissues in vivo. We demonstrate how to transplant pancreatic islets into the anterior chamber of the mouse eye.
Hello, I'm me Doretta from the Diabetes Research Institute at the University of Miami Miller School of Medicine. I will demonstrate in this video how to transplant pancreatic eyelets into the interior chamber of the mouse eye. The procedure involves two steps.
Step one is loading the isolated pancreatic eyelets into the cannula, and step two is the actual transplantation procedure. For details about instrumentation and reagents, please refer to the accompanying text. We highlight here, the motorized syringe driver with the syringe mounted and the reservoir and cannula attachments, which will be focused on in the following video.
We begin by loading the eyelets into the cannula. All procedures are performed under the stereoscope. Begin by centering the eyelets by spinning or rotating the dish in circles.
When centered, disconnect the cannula from the reservoir and flush out any air bubbles by driving the motorized syringe driver forward. And that is done by stepping on the forward foot pedal. When ready, begin aspirating the eyelets into the reservoir by now driving the motorized syringe driver in the backward direction.
And again, that's done by stepping on the backward foot pedal. Notice how the eyelets tend to accumulate in the bottom of the reservoir. Then reconnect the cannula to the reservoir and eject the eyelets out of the reservoir.
Then the tubing into the cannula to dislodge the eyelets out of the reservoir and encourage them to stay packed in the tubing. Tap the reservoir as you drive the motorized syringe driver forward. Notice how packed the eyelets are in the tubing as they begin entering the back of the cannula.
By now, you should be ready to transplant the eyelets. Place the NS sized mouse on a pad and expose or pop the eye to be transplanted by pulling on the head skin with your index finger and thumb. Using a new needle as scalpel.
Approach the eye with the beveled end facing downward to prevent contact and injury of the iris. Penetrate the tip of the needle into the cornea and make a lateral incision. Next, introduce the cannula, preloaded with eyelids into the interior chamber through the incision, and begin infusing the eyelets into the chamber again by driving the motorized syringe driver forward.
Do not worry about air bubbles that might be trapped inside the cannula as they will dissipate later. And they will act as a natural barrier to minimize or prevent reflux of the eyelids out of the chamber. Slowly and carefully retract the cannula out of the interior chamber.
Now wash the eye with sterile PBS. Inject your preferred analgesic, and finally, apply ophthalmic antibiotic ointment. The transplantation is finished.
We now show representative results featuring pancreatic eyelids transplanted into the interior chamber of the eye. For longitudinal imaging studies of the individual eyelets on day seven. After transplantation, the eyelets are clearly engrafted on top of the iris by day 28.
The eyelets are in the same locations as seen previously 42 days after transplantation. The eyelets are clearly visible in the same locations. Also notice how well the incision healed precluding any possibility of interfering with imaging of the individual eyelets.
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Overview
This article presents a novel method for transplanting pancreatic islets into the anterior chamber of the mouse eye, utilizing intraocular transplantation and confocal microscopy. This approach allows for longitudinal, non-invasive imaging of grafted tissues with single-cell resolution in vivo.
Key Study Components
Area of Science
- Neuroscience
- Transplantation Biology
- Imaging Techniques
Background
- Pancreatic islet transplantation is a potential treatment for diabetes.
- Traditional methods of monitoring grafts can be invasive and limited.
- Confocal microscopy provides high-resolution imaging capabilities.
- Intraocular transplantation offers a unique environment for graft monitoring.
Purpose of Study
- To demonstrate a method for transplanting pancreatic islets into the mouse eye.
- To enable real-time imaging of transplanted tissues.
- To assess the viability and integration of islets post-transplantation.
Methods Used
- Isolation of pancreatic islets.
- Loading islets into a cannula for transplantation.
- Performing the transplantation under a stereoscope.
- Using confocal microscopy for imaging post-transplantation.
Main Results
- Successful transplantation of pancreatic islets into the anterior chamber.
- Islets remained visible and viable for imaging up to 42 days post-transplant.
- Healing of the incision site was observed, allowing for clear imaging.
- Engraftment of islets was confirmed through longitudinal imaging studies.
Conclusions
- The method allows for effective monitoring of pancreatic islet transplants.
- Confocal microscopy provides valuable insights into graft dynamics.
- This approach could enhance understanding of islet biology and improve diabetes treatments.
Frequently Asked Questions
Executive Industry Relevance
Longitudinal, non-invasive in vivo imaging with single-cell resolution addresses a critical gap in preclinical research by enabling real-time monitoring of transplanted tissues and cellular dynamics. This platform supports high-content, quantitative analysis of tissue integration, survival, and response to interventions, directly informing target validation and mechanistic de-risking. Its versatility extends to drug screening and disease modeling, enhancing predictive confidence at key discovery and translational inflection points.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Enables direct visualization of transplanted tissues for functional target validation.
- Supports mechanistic de-risking by allowing real-time observation of cellular processes.
- Facilitates hypothesis testing in disease-relevant systems, such as islet transplantation models.
Screening & Assay Development
- Provides a platform for longitudinal drug screening with quantitative, single-cell resolution outputs.
- Enables reproducible, standardized imaging of tissue responses over time.
- Supports assay development for monitoring physiological and pathophysiological processes in vivo.
Translational & Preclinical Research
- Aligns with disease-relevant models for studying transplantation, cancer, and autoimmune disease development.
- Enables continuity from discovery through preclinical validation by tracking tissue fate and function.
- Supports risk-adjusted advancement decisions through non-invasive, longitudinal data collection.
Pipeline & Workflow Integration
This transplantation and imaging method integrates into the discovery-to-preclinical continuum by enabling real-time, quantitative monitoring of tissue and cellular dynamics in vivo.
- Discovery Biology: Supports hypothesis testing and pathway clarification through direct visualization of transplanted tissues.
- Screening: Delivers assay-ready, reproducible imaging outputs for drug and intervention evaluation.
- Analytics: Provides quantitative, longitudinal measurements for comparing experimental conditions and outcomes.
- Translational Research: Bridges discovery and preclinical phases by enabling disease-relevant, in vivo monitoring of tissue integration and function.
- Enterprise Reuse: Offers a versatile platform adaptable to various tissue types and disease models for repeated use across programs.
Operational & Enterprise Impact
- Scientific Value: Increases predictive confidence and reduces mechanistic ambiguity in tissue integration and function studies.
- Operational Value: Standardizes non-invasive, longitudinal imaging workflows with high reproducibility and scalability.
- Strategic Value: Improves go/no-go decision-making and capital efficiency by providing robust, real-time data.
- Portfolio Impact: Enables risk-adjusted prioritization and advancement of therapeutic candidates based on dynamic, in vivo evidence.
Implementation Considerations
- Requires expertise in microsurgical transplantation and advanced imaging techniques.
- Demands access to stereoscopic and confocal microscopy infrastructure for single-cell resolution imaging.
- Necessitates cross-team standardization of transplantation and imaging protocols for reproducibility.
- Adaptable to various tissue types and disease models with appropriate procedural modifications.
- Potential limitations include technical complexity and the need for specialized instrumentation.
