Longitudinal Intravital Imaging Through Clear Silicone Windows.

Area of Science:

• * Biomedical Engineering
• * Cell Biology
• * Microscopy

Background:

• * Intravital microscopy (IVM) provides single-cell resolution for observing dynamic biological processes.
• * Current glass-based imaging windows cause discomfort and inflammation in mice, limiting long-term studies.
• * Existing windows can fail, necessitating euthanasia and interrupting critical longitudinal observations.

Purpose of the Study:

• * To develop and evaluate novel polydimethylsiloxane (PDMS) imaging windows for improved long-term intravital microscopy.
• * To overcome limitations of traditional glass-metal windows, including reduced invasiveness and enhanced durability.
• * To enable precise tracking of specific tissue regions for longitudinal studies.

Main Methods:

• * Developed flexible PDMS imaging windows with embedded stainless-steel grids.
• * Utilized PDMS windows for direct tissue adhesion, simplifying insertion.
• * Tested window durability and inflammatory response in mice over 35 days.
• * Employed PDMS windows for longitudinal imaging of abdominal organs, mammary glands, and cancer metastasis.

Main Results:

• * PDMS windows demonstrated flexibility and durability for up to 35 days in mice.
• * Silicone windows significantly reduced inflammation compared to traditional methods.
• * Embedded grids facilitated accurate localization of tissue regions for repeated imaging sessions.
• * Successfully monitored dynamic processes like mammary gland involution and cancer cell metastasis over time.

Conclusions:

• * PDMS imaging windows offer a simpler, less invasive alternative for long-term intravital microscopy.
• * These windows enhance the ability to conduct longitudinal studies of cellular dynamics and disease progression.
• * The embedded grid system ensures precise tracking of anatomical locations across multiple imaging sessions.