# Engineered microbubbles to augment laser lithotripsy of urinary stones

> **NIH NIH R43** · APPLAUD MEDICAL, INC. · 2021 · $256,539

## Abstract

Abstract
Significance: Ureteroscopic laser lithotripsy is currently the most common surgical treatment for urinary
stones—a painful disease affecting 1 in 11 people and imposing a significant burden on the U.S.
healthcare system, with the cost of care exceeding $10 billion annually. Although laser lithotripsy breaks
all types of stones, an emergent concern is that a large fraction of patients (around one in two) is left
with residual stone fragments when evaluated with computed tomography that are too small to laser
efficiently but too large to pass spontaneously with urine flow. While the residual fragments are small in
comparison with the pre-treatment stone, the residual fragments nonetheless lead to high rates of post-
operative emergency department visits, additional interventions, and recurrence of stones.
Preliminary studies suggest that specially engineered microbubbles augment laser lithotripsy, producing
smaller residual fragments, which should lead to improved clinical outcomes. We hypothesize that
engineered microbubbles augment laser lithotripsy by focusing energy into stones and stone fragments
via two main mechanisms: optical and mechanical. This is consistent with the mechanisms by which
conventional laser lithotripsy ablates urinary stones, via direct laser light interactions with the stone
surface as well as mechanical effects due to the rapid vaporization and subsequent violent collapse of
the aqueous environment concomitant with each laser pulse.
The objective of this Phase I SBIR is to determine the feasibility of using specially engineered
microbubbles to significantly reduce residual stone fragments and improve laser lithotripsy. In Aim 1,
we will identify mechanisms and sites of action of engineered microbubbles in laser lithotripsy. In Aim 2,
we will develop strategies to improve the effectiveness of laser lithotripsy with engineered microbubbles.
The innovation of the proposed approach is the use of engineered microbubbles that accumulate on
urinary stones to augment stone fragmentation and reduce residual stone fragments in laser lithotripsy.
This approach has the potential to significantly improve the treatment for urinary stones by reducing the
risk of injury, procedural complications, and additional procedures, as well as result in a significant
reduction in procedural time and cost. In addition, the knowledge gained from this feasibility study will
aid our understanding of the mechanisms by which conventional laser lithotripsy operates, and produce
further insights into the treatment of biomineralization-related diseases.

## Key facts

- **NIH application ID:** 10255749
- **Project number:** 1R43DK129104-01
- **Recipient organization:** APPLAUD MEDICAL, INC.
- **Principal Investigator:** Yuri A. Pishchalnikov
- **Activity code:** R43 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $256,539
- **Award type:** 1
- **Project period:** 2021-05-15 → 2023-05-14

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10255749

## Citation

> US National Institutes of Health, RePORTER application 10255749, Engineered microbubbles to augment laser lithotripsy of urinary stones (1R43DK129104-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10255749. Licensed CC0.

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