Jessica Gidzinski, David Pearson, Travis WeissAdvisor: Dr. Michele Marcolongo

Mentors: Alicia Kriete, Evan Phillips, Dr. Katsiaryna Prudnikova

Novel Use of Biomimetic Proteoglycans to Molecularly Engineer the Extracellular Matrix of Damaged Skin

1

Problem Statement

Problem: As skin ages, it dehydrates and loses compliance.

• Vulnerability to wounds/infectiono 92% of institutionalized elderly

sustain at least 1 skin tear every year• Wrinkles

2MALONE, ML, et al. "the Epidemiology of Skin Tears in the Institutionalized Elderly."JOURNAL OF THE AMERICAN GERIATRICS SOCIETY 39.6 (1991): 591-5. Web.

and proteoglycans (ECM molecules)

Skin Layers and Molecular Composition● Epidermis● Dermis● Hypodermis● ECM: offers structural and

biochemical support○ Structural proteins○ Glycoproteins○ Proteoglycans (PGs): embed

structural proteins & are critical for wound healing■ PG breakdown over time

causes dehydration and reduced compliance

ECM

3reading.ac.ukheadandneckcancerguide.org

Proteoglycans

Protein core with covalently attached glycosaminoglycan (GAG) chains

Functions:

• Mechanical: o Increased water uptake (hydration)→

negatively charged GAG chains• Biological:

○ PGs aid in last 2 stages of wound healing1. Cell migration/proliferation (fibroblasts)2. Remodelling: bind to type I collagen fibers

in skin to align them in organized fashion

4sci.utah.edu

Proposed Solution - Biomimetic Proteoglycans (BPGs)

• Increased hydration & compliance• Restored PG content could potentially

enhance wound healingo PGs align collagen fibers during

wound healingo High PG content→less scarring

5

Degenerated Tissue

Restored Tissue (Hydration/Swelling)

Marcolongo, M. "Matrix Molecular Engineering Using Biomimetic Proteoglycans." 26 Oct. 2015. Lecture.Lightfoot Vidal, Sarah Eugenia, Michele S. Marcolongo and Drexel University. College of Engineering. "Novel Biomimetic Aggrecan for the Acellular Regeneration of the Intervertebral Disc: Synthesis, Enzymatic Stability and Molecular Engineering." 2013. Web.

PAA

CS GAG Chains

Objectives and Methods

Objective 1: Determine if BPGs have a statistically significant effect on skin compliance

Method: Employ piezoelectric finger (PEF) method to measure elastic modulus of BPG-injected porcine skin samples

Objective 2: Evaluate the diffusion behavior of BPGs in skin

Method: Cryosection samples thin enough to view under confocal microscope; quantify percent area fluorescence of tagged BPGs at varying distances from injection site

6

Piezoelectric Finger (PEF) Method

Xu, Xin, Cynthia Gifford-Hollingsworth, Richard Sensenig, Wei-Heng Shih, Wan Shih, and Ari D. Brooks. "Breast Tumor Detection Using Piezoelectric Fingers: First Clinical Report." Vol. 216, No. 6. Drexel University, June 2013.

7

Exceeded target of 25% reduction in modulus (increased compliance)

Confocal MicroscopyEmbedding Mold

Leica 1850 Cryostat

8

Confocal Microscopy Images

9

Confocal Microscopy Results

10

● Decrease in amount of molecule near injection sites over 24 hr period

● Overall, molecular level integration with existing extracellular matrix and diffusion around injection site is shown over a 24 hr period.

Overall Conclusions and Design Considerations• For the first time, demonstrated molecular

engineering of the ECM of porcine skin using

biomimetic proteoglycans.

• The skin hydration and increased compliance

caused by injectable BPGs offers potential for

treatment of diseased and aged skin against

tearing and subsequent infection. o An injection of natural PGs can cost $300/mg

while an injection of BPGs typically costs

$0.06/mg. 11