Skin collagen can be accurately quantified through noninvasive optical method: Validation on a swine study

Area of Science:

• Biomedical Optics
• Dermatology
• Optical Engineering

Background:

• Diffuse reflectance spectroscopy (DRS) is a cost-effective, noninvasive optical technology.
• Previous studies quantified relative collagen concentration in keloids but lacked absolute values for reliability.
• Establishing absolute collagen concentration is crucial for validating DRS accuracy in skin assessment.

Purpose of the Study:

• To validate the reliability of DRS for quantifying absolute collagen concentration in skin.
• To assess the influence of other chromophores, like coffee, on collagen quantification.
• To compare DRS collagen measurements with established histological methods.

Main Methods:

• Prepared skin-mimicking phantoms with varying collagen and coffee concentrations.
• Quantified chromophore concentrations using the DRS system in phantoms.
• Conducted an animal study comparing DRS measurements with second-harmonic generation (SHG) microscopy of biopsy sections.

Main Results:

• Phantom studies indicated minimal interference from coffee chromophores on collagen quantification.
• A strong positive correlation (r=0.902) was observed between DRS and SHG microscopy in animal skin.
• DRS successfully quantified absolute collagen concentrations, unaffected by other chromophores in phantoms.

Conclusions:

• DRS can reliably quantify absolute collagen concentration in skin, independent of other chromophores.
• The high correlation with SHG microscopy validates DRS as an objective tool for skin evaluation.
• DRS presents a promising noninvasive technique for assessing skin conditions.