New bioprocesses for CPD-photolyase extraction may improve sunscreen safety, research reveals

23 Aug 2022 --- Researchers in Chile have developed a new approach for the induction and extraction of cyclobutane pyrimidine dimer (CPD)-photolyase – repair enzymes – with applications for the cosmetic and dermatology industries. The process yields a 5.5 times increase of CPD in comparison to the protein extract from standard production bioprocesses.

The induction of the CPD-photolyase solution from the cyanobacterium Synechococcus leopoliensis during the cyanobacterium growth and its extraction by an aqueous two-phase system (ATPS) was evaluated in the study published in the Journal of Applied Phycology.

Due to its catalytic reaction, skincare products with encapsulated CPD-photolyase in liposomes have been shown to reduce the ultraviolet (UV)-induced DNA skin damage and prevent the detrimental effects of UV exposure to patients with nucleotide excision repair (NER) deficiency, non-melanoma skin cancer and photoaging.

Dermatologists recommend using sunscreen with DNA repair enzymes in patients susceptible to skin cancer.DNA repair enzymes for sun protection
Dermatologists recommend using sunscreen with DNA repair enzymes in patients susceptible to skin cancer. The CPD-photolyase enzyme specifically recognizes and repairs these DNA damages via photoreactivation by cleaving the cyclobutane ring from the thymine – thymine CPD.

CPD-photolyase is a monomeric protein of 55 to 70 kilodalton (kDa) that contains two non-covalently bound prosthetic groups, flavin adenine dinucleotide (FAD) and a pterin (or deazaflavin). It is present in animals, plants, and bacteria but absent in placental animals such as humans.

The cyanobacterium Synechococcus sp. is the primary source of CPD-photolyase. A protein extract of Synechococcus leopoliensis containing CPD-photolyase is encapsulated in liposomes and used in lotions or creams.

New trials for improved extraction
Several methods are described for the purification of photolyases but involve multiple chromatographic steps with many exchanges of dialysis buffers. However, these methods are not suitable for large scale due to batch processing, large pressure drops and activity loss.

Researchers experimented with ATPS for the first time in the extraction of CPD-photolyase, allowing a one-step extraction from the biomass.

ATPS is a liquid-liquid method formed by two hydrophilic but immiscible aqueous solutions, which confers a good enzyme environment for its activity preservation. 

The method has gained attention to overcome the purification disadvantages in protein downstream bioprocessing.

Its applications and scale-up have been shown to recover and purify enzymes from different microorganism protein extracts. Additionally, it is a simple, time-efficient and low-cost method.

The ATPS is optimized according to the composition and physicochemical properties of the protein. The main factors influencing the partition are molecular weight or concentration of the polymer, hydrophobicity, pH, and temperature.

The phases of ATPS are composed of a polymer upper phase (e.g., dextran or polyethylene glycol (PEG)) and polymer or salt as a lower phase.

ATPS could represent an alternative to improve CPD-photolyase downstream bioprocessing.

Moreover, this ATPS also extracted c-phycocyanin in the PEG phase, which has essential bioactivity properties and could complement skincare products based on CPD-photolyase.

The work carried out by Chilean researchers aimed to produce an enriched CPD-photolyase solution from the cyanobacterium S. leopoliensis, with higher activity than the traditional culture and extraction processes.

Cosmetic application Placental mammals have undergone an evolutionary loss of photolyases.
Photolyases are flavoproteins that repair ultraviolet-induced DNA lesions using blue light as an energy source.

The high and steadily increasing incidence of UV-induced skin cancer is a problem recognized worldwide. UV introduces different types of damage to the DNA. If unrepaired, these photolesions can give rise to cell death, mutation induction and the onset of carcinogenic events.

As placental mammals have undergone an evolutionary loss of photolyases, they can only repair UV-induced DNA damage by the elaborate nucleotide excision repair pathway. This is why the use of sunscreen with CPD-repair enzymes is seen as essential.

Sunscreen developments
Earlier this year, Symrise unveiled its cosmetic brand Neo Heliopan, a mineral UV filter range developed under its care segment and with its strategic partner Kobo, a company specializing in mineral UV filters, to meet the increasing demand for effective, safe and natural sun care.

The addition of two launches to its mineral sun care portfolio is dubbed Neo Heliopan ZnO 300 and Neo Heliopan ZnO 40. While both provide broad-spectrum UV protection, the first has a larger particle size (non-nano), and the latter offers UVB protection with no white cast due to its fine particle size (nano).

Solésence Beauty Science won the Cosmopack Award for Formulation for its Multi-Cultural Magic SPF 50+, designed with a clean formulation based on mineral UV protection.

The sunscreen features Solésence’s Korea patented Kleair, a new generation of high-transparency zinc oxide mineral sunscreen with “enhanced” UV blocking properties. 

Earlier this month, Thai researchers identified Antidesma thwaitesianum fruit extracts to potentially be utilized as a skincare ingredient for preventing UVB-induced skin damage.

Significant amounts of bioactive polyphenol and flavonoid compounds, such as anthocyanin, catechin and gallic acid were found in this fruit. 

To inform people worldwide about the importance of UV protection and reduce skin cancer cases and UV-related eye damage, UN agencies launched the SunSmart Global UV app that provides a five-day UV and weather forecast and notifies users when sun protection is needed.

By Radhika Sikaria