# Smart Photodynamic Therapy for Acne by Reversibly Switchable Intersystem Crossing in Pure Organic Materials

> **NIH NIH R43** · ADVANCED CYTOMETRY INSTRUMENTATION SYS · 2022 · $258,600

## Abstract

Abstract –
Acne vulgaris is the most common skin condition in the United States, affecting up to 50 million Americans
annually. While acne is common in young people, this condition becomes increasingly widespread in adults,
especially in females— chronic post-adolescent acne affects about 15 percent of women in the USA. Moderate
to severe acne confers a tremendous medical, psychological, and economic health care burden on the US
population. The development of acne is multifactorial, but centers around the sebaceous glands (SG), which are
the microscopic holocrine glands within the skin dermis. SGs comprise specialized cells—sebocytes—that
secrete a variety of lipids composing the sebum. Conventional clinical treatment of severe inflammatory acne
involves a combination of topical and systemic drugs, administered over the course of several months or even
years. These include topical and oral retinoids, antibiotics, and in some instances, hormonal therapy. Treatment
is often ineffective and carries the risk of adverse side effects. Remarkably, photodynamic therapy (PDT) has
shown breakthrough potential for dermatology. PDT involves topical application of agents called photosensitizers
(PS) to the affected skin area. When exposed to specific wavelengths of light, these agents generate highly
cytotoxic singlet oxygen (1O2 ) that damages sebocytes, reducing both the size and activity of SGs, and locally
eliminates bacterial infections. However, use of conventional PDT includes a significant risk of skin damage as
the 1O2 inherently damages fibroblasts, epithelium, and other skin components outside the SG in the entire
irradiated skin area. The unintended photodamage has an adverse effect on skin structure and function and can
potentially lead to cancer. Thus, the utility of conventional PDT is limited because of these significant side effects.
To address this limitation, ACIS is developing a Smart PDT (S-PDT) platform will enable targeted and
tunable treatment to cells of the SGs, while sparing other cell types. As part of this, ACIS is developing a
next generation PS agent that is designed to be active selectively in the sebum producing cells of SGs and
bacteria-infected sites, while causing no damage to the surrounding healthy tissue. This approach alleviates the
common photodynamic therapy limitations via reversible on/off switching of intersystem crossing in small organic
molecules, thereby boosting (in “on” mode) or suppressing (in “off” mode) singlet oxygen production. The Specific
Aims of this Phase I project are as follows : 1) Design and synthesize a reversibly switchable pH-sensitive PS
with tunable isoelectric point and tunable absorption maximum to penetrate the skin at the optimal depth; and 2)
Demonstrate the viability of the S-PDT approach via in vitro and ex vivo tests, including cellular uptake,
cytotoxicity, and PDT action of newly synthesized materials in human skin models. Successful completions of
these aims will demonstrate the vi...

## Key facts

- **NIH application ID:** 10483461
- **Project number:** 1R43AR079947-01A1
- **Recipient organization:** ADVANCED CYTOMETRY INSTRUMENTATION SYS
- **Principal Investigator:** Dalar Bansal
- **Activity code:** R43 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $258,600
- **Award type:** 1
- **Project period:** 2022-09-22 → 2023-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10483461

## Citation

> US National Institutes of Health, RePORTER application 10483461, Smart Photodynamic Therapy for Acne by Reversibly Switchable Intersystem Crossing in Pure Organic Materials (1R43AR079947-01A1). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10483461. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*