MP29-08: Effect of stone-targeting nanomaterials on fragment size using photonic lithotripsy
Saturday, May 4, 2024 9:30 AM to 11:30 AM · 2 hr. (US/Central)
302B
Abstract
Information
Full Abstract and Figures
Author Block
Ian Houlihan*, Avisha Pandey, Smita De, Vijay Krishna, Cleveland, OH
Introduction
Kidney stones affect ~10% of individuals in the USA. The most common stone surgeries include laser lithotripsy by ureteroscopy and extracorporeal shock wave lithotripsy. Photonic lithotripsy (PL) is a novel technology being developed for minimally invasive, non-contact kidney stone treatment. PL utilizes photonic nanoparticles that are activated by low-intensity (< 5 W), near-infrared laser energy to produce photothermal and/or photoacoustic energy that results in stone fragmentation. We investigated the effect of modifying photonic nanoparticles with targeting ligands on the efficacy of stone fragmentation.
Methods
Calcium phosphate (CaP) human kidney stones with a size of ~ 4 mm were obtained from the Cleveland Clinic Pathology Lab. Non-targeting polyhydroxy fullerenes (PHF) and stone-targeting polyhydroxy fullerenes (tPHF, t=bisphosphonate) were tested. Stones were soaked in 10 mg/mL of PHF or tPHF for 10, 20 or 30 minutes, removed from the solution and exposed to a 785 nm NIR laser (1 W) at a distance of 20 mm until failure of the stone occurs. The degree of success for the treatment was determined by sieving the stone fragments through 4 mm, 2 mm and 1 mm sieves and calculating the weight fraction of the stone fragments in each sieve.
Results
Stones showed a marked difference in fragment size when treated with tPHF vs. PHF (Figure 1) with a shift toward smaller size fractions using the targeting nanoparticles. This is seen with an increase in the average mass fraction of < 1 mm fragments (10 minutes soaking) from 0.16 to 0.4 for PHF and tPHF respectively. There is also a shift to smaller fragment sizes with an increase in soaking time in the nanoparticle solution. A greater volume fraction of <1 mm stone fragments was recorded when increasing from 10 to 20 minutes soak time with both PHF and tPHF (Fig 1a and 1b). Prior experiments have shown no stone fragmentation with the absence of PHF and laser energy alone.
Conclusions
Stone-targeted PHF is more effective at fragmenting CaP stones into smaller size fractions when compared to PHF without a targeting ligand. This was achieved at low energy and in a non-contact mode (20 mm from the stones surface).
Source Of Funding
LRI Accelerator Grant, Cleveland Clinic Caregiver Catalyst Award, U2Csupport 1U2CDK129440, Morrison Family.
Author Block
Ian Houlihan*, Avisha Pandey, Smita De, Vijay Krishna, Cleveland, OH
Introduction
Kidney stones affect ~10% of individuals in the USA. The most common stone surgeries include laser lithotripsy by ureteroscopy and extracorporeal shock wave lithotripsy. Photonic lithotripsy (PL) is a novel technology being developed for minimally invasive, non-contact kidney stone treatment. PL utilizes photonic nanoparticles that are activated by low-intensity (< 5 W), near-infrared laser energy to produce photothermal and/or photoacoustic energy that results in stone fragmentation. We investigated the effect of modifying photonic nanoparticles with targeting ligands on the efficacy of stone fragmentation.
Methods
Calcium phosphate (CaP) human kidney stones with a size of ~ 4 mm were obtained from the Cleveland Clinic Pathology Lab. Non-targeting polyhydroxy fullerenes (PHF) and stone-targeting polyhydroxy fullerenes (tPHF, t=bisphosphonate) were tested. Stones were soaked in 10 mg/mL of PHF or tPHF for 10, 20 or 30 minutes, removed from the solution and exposed to a 785 nm NIR laser (1 W) at a distance of 20 mm until failure of the stone occurs. The degree of success for the treatment was determined by sieving the stone fragments through 4 mm, 2 mm and 1 mm sieves and calculating the weight fraction of the stone fragments in each sieve.
Results
Stones showed a marked difference in fragment size when treated with tPHF vs. PHF (Figure 1) with a shift toward smaller size fractions using the targeting nanoparticles. This is seen with an increase in the average mass fraction of < 1 mm fragments (10 minutes soaking) from 0.16 to 0.4 for PHF and tPHF respectively. There is also a shift to smaller fragment sizes with an increase in soaking time in the nanoparticle solution. A greater volume fraction of <1 mm stone fragments was recorded when increasing from 10 to 20 minutes soak time with both PHF and tPHF (Fig 1a and 1b). Prior experiments have shown no stone fragmentation with the absence of PHF and laser energy alone.
Conclusions
Stone-targeted PHF is more effective at fragmenting CaP stones into smaller size fractions when compared to PHF without a targeting ligand. This was achieved at low energy and in a non-contact mode (20 mm from the stones surface).
Source Of Funding
LRI Accelerator Grant, Cleveland Clinic Caregiver Catalyst Award, U2Csupport 1U2CDK129440, Morrison Family.