ABSTRACT
This research aims to
obtain useful information for development of medical devices such as wound
dressing and tissue anti-adhesive product, using a spongy sheet composed of
hyaluronic acid (HA) and collagen (Col). The spongy sheets were manufactured by
freeze vacuum drying of HA and Col aqueous solution, followed by UV irradiation
to introduce intermolecular crosslinks between Col molecules. These spongy
sheets are referred to as Sponge-A (ratio of HA/Col = 5/1) and Sponge-B (ratio
of HA/Col = 5/5). Both surfaces of Sponge-A and Sponge-B treated with UV
irradiation for 15 minutes are referred to as Sponge-A-15 and Sponge-B-15,
respectively. The weight change of spongy sheet was determined by immersing a
peace of spongy sheet in water at 37°C. The weight of sponge-A-15 collected 1/2, 1, 3, 7 days after immersion
in water was 63.5%, 62.1%, 56.6%, 54.4% of the original weight, respectively.
The weight of Sponge-B-15 was 78.3%, 76.7%, 79.1%, 71.9% of the original
weight, respectively. The weight change of spongy sheet was determined by
immersing a peace of spongy sheet in water containing collagenase at 37°C. The weight of Sponge-A-15 collected 6, 8, 10, 12
hours after immersion in water containing collagenase (0.0005 w/v%) was 65.7%, 59.8%,
57.9%, 55.2% of the original weight, respectively. The weight of Sponge-B-15
was 63.5%, 52.1%, 42.0%, 43.2% of the original weight, respectively. This
spongy sheet is considered to have the unique structure, where HA molecules are
entrapped in an intermolecular cross-linked network structure of Col molecules.
When immersed in water containing collagenase, the weight loss of spongy sheet
is accelerated by easy extraction of HA molecules from the enzymatic degraded
Col network structure. The performance of wound dressing and tissue anti-adhesive
product is considered to depend on appropriate ratio of HA and Col, and also on
appropriate rate of intermolecular crosslinks between Col molecules. These
findings obtained in this study provide useful information for product
development such as wound dressing and tissue anti-adhesive product.