Assessing a Natural Product Plus Bioadhesive Nanoparticle (BNP) Sunscreen

Skin cancer is the most commonly diagnosed malignancy in the USA and ultraviolet radiation (UVR) exposure is the major environmental risk factor for skin cancer development. Currently available sunscreens utilize UVR filters that, while absorbing UVR energy, have been shown to induce ROS, resulting in oxidative DNA damage after UVR exposure. Organic sunscreen actives have also been shown to penetrate into the skin, raising direct toxicity, as well as irritant and photoallergic concerns. Further systemic absorption may result in additional health risks such as endocrine disruption. Novel sunscreens that more safely prevent both direct and indirect DNA damage are needed.

The study team have produced a bioadhesive nanoparticle (BNP) sunscreen designed to keep organic UVR filters from penetrating into the skin and have incorporated non-toxic natural products into this sunscreen to further safely boost UVR absorbing capacity and reduce oxidative, indirect DNA damage. This study will test the capacity of this sunscreen to prevent direct and indirect cellular and DNA damage in human skin exposed to UVR.

• Sunscreen (Drug): The sunscreen contains bioadhesive nanoparticles (BNP) encapsulating avobenzone and octocrylene plus the non-toxic natural products diosmin, ferulic acid, cytisine and trans-resveratrol.
• UV Light (Other): UV light to the correct sites, and the Multiport 610 solar simulator used to deliver 1 MED UVR to the appropriate subsites.

Primary outcomes

• DNA Damage Level by Cyclobutane Pyrimidine Dimer (CPD) Measurement [5 minutes after UVR exposure]: Ultraviolet radiation (UVR) exposure are indicative of direct DNA damage. DNA will be prepared and assayed by ELISA for quantification of CPDs. CPDs measured in samples obtained immediately after UVR exposure are indicative of direct DNA damage. DNA from skin biopsies was used to quantify the level of DNA damage, represented by CPD levels detected by enzyme-linked immunosorbent assay (ELISA)
• DNA Damage Level by Cyclobutane Pyrimidine Dimer (CPD) Measurement [4 hours after UVR exposure]: Ultraviolet radiation (UVR) exposure are indicative of direct DNA damage. DNA will be prepared and assayed by ELISA for quantification of CPDs. CPDs measured in samples obtained immediately after UVR exposure are indicative of direct DNA damage. DNA from skin biopsies was used to quantify the level of DNA damage, represented by CPD levels detected by enzyme-linked immunosorbent assay (ELISA)
• Detectable DNA Strand Breaks [5 minutes after UVR exposure]: Formalin fixed paraffin embedded skin stained with anti-gH2AX to identify keratinocytes with DNA strand breaks. Indirect, oxidative DNA damage may result in DNA strand breaks that can be visualized by microscopic analysis after staining for gH2AX, which builds up within cells with DNA strand break.
• Number of DNA Strand Breaks [4 hours after UVR exposure]: Formalin fixed paraffin embedded skin stained with anti-gH2AX to identify keratinocytes with DNA strand breaks. Indirect, oxidative DNA damage may result in DNA strand breaks that can be visualized by microscopic analysis after staining for gH2AX, which builds up within cells with DNA strand break.
• Cellular Damage [5 minutes after UVR exposure]: Formalin fixed paraffin embedded skin stained with anti-3-nitrotyrosine to identify cellular damage. ROS and high energy triplet state species can result in nitration of tyrosine residues of cellular proteins. This type of damage can be visualized by microscopic visualization of 3-nitrotyrosine.
• Cellular Damage [4 hours after UVR exposure]: Formalin fixed paraffin embedded skin stained with anti-3-nitrotyrosine to identify cellular damage. ROS and high energy triplet state species can result in nitration of tyrosine residues of cellular proteins. This type of damage can be visualized by microscopic visualization of 3-nitrotyrosine.

Sex: All, ages: 18 Years to any, accepts healthy volunteers

Inclusion Criteria:

* Provision of signed and dated informed consent form
* Stated willingness to comply with all study procedures and availability for the duration of the study
* Women of child-bearing potential must have negative urine pregnancy test
* In good general health as evidenced by medical history
* Fair skinned with Fitzpatrick Scale skin types I, II or III using the following Skin Type and Sunburn and Tanning History (based on the first 30-45 minutes of sun exposure after a winter season of no sun exposure):
* I always burns easily; never tans (sensitive)
* II always burns easily; tans minimally (sensitive)
* III burns moderately; tans gradually (light brown) (normal)

Exclusion Criteria:

* Individuals with active or a history of dermatological disorders-psoriasis, rosacea, eczema, vitiligo, lupus, dermatomyositis, etc
* Individuals known to be subject to any abnormal responses to sunlight, such as phototoxic or photoallergic response.
* Current use of medication (topical or systemic) that is known to produce abnormal sunlight responses.
* History of skin cancer (such as basal cell carcinoma, squamous cell carcinoma, melanoma)
* Family history of melanoma
* Presence of sunburn, suntan, scars, active dermal lesions or uneven skin tone on the test site.
* Skin type falling under the Fitzpatrick Scale skin types IV, V or VI using the following Skin Type and Sunburn and Tanning History (based on the first 30-45 minutes of sun exposure after a winter season of no sun exposure):
* IV Burns minimally; always tans well (moderate brown) (normal)
* V Rarely burns; tans profusely (dark brown) (insensitive)
* Use of sunscreen within the last week on the test site area (such that UV filter penetration may confound results)
* Febrile illness within 48 hours.
* Women with a positive urine pregnancy test

Participant flow

Outcome results

• DNA Damage Level by Cyclobutane Pyrimidine Dimer (CPD) Measurement (Primary), Mean, Optical Density Units: Sunscreen Formulation 1 2.48 +/- 0.15; Sunscreen Formulation 2 2.18 +/- 0.14; Sunscreen Formulation 3 2.64 +/- 0.09 (p 0.003)
• DNA Damage Level by Cyclobutane Pyrimidine Dimer (CPD) Measurement (Primary), Mean, Optical Density Units: Sunscreen Formulation 1 2.41 +/- 0.21; Sunscreen Formulation 2 2.07 +/- 0.14; Sunscreen Formulation 3 2.42 +/- 0.08
• Detectable DNA Strand Breaks (Primary), Mean, fluorescence units: Sunscreen Formulation 1 0 +/- 0; Sunscreen Formulation 2 0 +/- 0; Sunscreen Formulation 3 0 +/- 0
• Number of DNA Strand Breaks (Primary), Mean, fluorescence units: Sunscreen Formulation 1 0 +/- 0; Sunscreen Formulation 2 0 +/- 0; Sunscreen Formulation 3 0 +/- 0
• Cellular Damage (Primary), Mean, fluorescence units: Sunscreen Formulation 1 0 +/- 0; Sunscreen Formulation 2 0 +/- 0; Sunscreen Formulation 3 0 +/- 0
• Cellular Damage (Primary), Mean, fluorescence units: Sunscreen Formulation 1 0 +/- 0; Sunscreen Formulation 2 0 +/- 0; Sunscreen Formulation 3 0 +/- 0

Adverse events

Time frame: 24 hours

• Study Protocol and Statistical Analysis Plan (PDF, 2023-02-21)
• Informed Consent Form (PDF, 2023-02-21)

• Michael Girardi, MD, FAAD, Principal investigator, Evans Professor of Dermatology; Director, Residency Program, Dermatology

NIH grants: P50CA121974