(C-118) Histological Evaluation of Human Hair as a Biomaterial

Friday, October 13, 2023

9:30 AM – 10:30 AM PDT

Location: Exhibit Hall - Row C - Poster # 118

Presenting Author(s)

AM

Allison Meer

Undergraduate Researcher
Hofstra University, United States

Co-Author(s)

AM

Aidan A. Mathews

Undergraduate Researcher
Hofstra University, United States
PC

Phoebe Christake

Undergraduate Researcher
Cornell University, United States

Primary Investigator(s)

Rd

Roche de Guzman, PhD

Associate Professor
Hofstra University
Hempstead, New York, United States

Introduction:: Introduction: An inexpensive and easily obtainable material, hair, is composed of distinct layers: cuticle, cortex, and medulla (for some). Cortical cells make up most of the hair fiber’s mass containing tightly disulfide-bound structural proteins: rod-shaped intermediate filaments of Type I and II hair keratins and globular matrix keratin-associated proteins (KAPs). The goal of the project was to investigate the potential for human hairs as implantable tissue-engineering biomaterials. In this study, various hair treatments were implemented to fractionate and remove extractable components producing 4 chemically different hair implantable groups: regular hair (REG), bleached hair (BLH), moderate KAPs (M-KAP), and Low KAPs (L-KAP).

Materials and Methods::

Materials and Methods: Eight mice samples were subcutaneously implanted with the four different hair treatment groups in the ventral chest cavity for a duration of two weeks. Regular hair was used as a control. The next group was bleached to denature the melanin within the cortex. The M-KAP group was moderately treated to remove the keratin associated proteins and partially degrade the cuticle to expose purer keratin found deeper within the hair strands. The final group was the L-KAP which was altered more to contain a low amount of KAPs and to mostly degrade the hair cuticle, thus exposing a higher amount of pure keratin. After two weeks, the implants and surrounding tissue were recovered to compare the fibrous/immunogenic tissue formation as a foreign body response to the implants. Histological processing and assessment were then conducted. Samples were fixed in formalin, dehydrated, embedded in paraffin, sectioned with a microtome, mounted on slides, and stained with Masson’s Trichrome dye to identify connective tissue genesis.

Results, Conclusions, and Discussions::

Results and Discussion: GIMP and Image-J processing and area measurements were used to compare the fibrous capsules of the groups. Measured areas included: A = total image, AS = entire intact sample slice, AG = internal spaces or gaps within AS, AI = hair implants, AT = fibrous (and immune) tissue responses, and AI/AT = ratio of implant to fibrous tissue. Significantly high AI/AT ratio was observed in the L-KAP group compared to regular hair, suggesting that KAPs are responsible to generating a thick fibrous capsule foreign body response (p < 0.01). Both the M-KAP and L-KAP groups contained a significantly high difference in AI/AT ratio when compared with BLH (p < 0.05).

Conclusion: After undergoing treatment to degrade the cuticle and remove KAPs, hair displays properties of reducing fibrous encapsulation and compatibility in comparison to regular hair. As supported by the results, it appears that the thick fibrous tissue predominantly emerges because of KAPs. Therefore, hair that contains only pure keratins and melanin, with a degraded cuticle layer, can potentially be used as a biocompatible implantable biomaterial to deliver varying medications and other implants.

Acknowledgements (Optional): :

Acknowledgements: Fusion Beauty Salon, Stylush Salon and Laser, Fresh Cuts, and Hair Designers for

sources of human hair samples.

References (Optional): :