Eye-drying agent with
an excellent hemostatic effect

Hypro-Sorb O is pure, native, 99.9% crystalline, resorbable, bovine, sterile atelocollagen. It is used especially in ophthalmology and neurosurgery for drying and to stop bleeding of the incision area. Owing to its triangular shape, the product can also be readily applied to areas of the body that are difficult to access.

Collagen that has been freed from telopeptides (which act as antigenic determinants) while preserving its quasi-crystalline, regularly arranged triple helical conformation, is referred to as atelocollagen. The assets of this material include the highest biocompatibility, excellent tolerance by living tissue and resorbability after implantation. Atelocollagen does not promote microorganism growth and has a mild bacteriostatic effect.

When is Hypro-Sorb O used?

Drying of the surgical field is among the routine procedures in ophthalmology and neurosurgery. Pieces of absorbent material are used for this purpose. The majority of the drying materials used for drying small wounds is based on cellulose. Hypro-Sorb O is one of the materials designed for this purpose; it is, however, made of pure atelocollagen. While comparable to cellulose regarding its drying capacity, atelocollagen is, in addition, an efficient hemostatic. Thus it helps to dry the surgical field and also stops capillary bleeding, which greatly facilitates the surgeon’s work, especially in microsurgery.

What are the advantages of atelocollagen-based drying?

The routinely used cellulose and collagen are both natural polymeric substances. Cellulose is of plant origin; hence, animal tissues perceive cellulose as a foreign organic substance. By contrast, collagen is a frequent and important component of animal tissues. Collagen is present in the tendons, bones, skin, and in the eye in the cornea, vitreous body and sclera. Collagen of various animal species differs slightly because in the peripheral parts of the macromolecule there are small areas referred to as telopeptides, which act as antigenic determinants. Their removal gives rise to atelocollagen, whose properties are basically identical to those of collagen but which is non-immunogenic. Therefore, it is biologically tolerated by the tissues, and any fragments left in a wound are resorbed without unwanted inflammatory response. The main asset of atelocollagen when used to dry wounds is in its extraordinary hemostatic effect in stopping capillary bleeding. Thus atelocollagen provides both good drying and efficient hemostasis during surgery.

How is hemostasis activated?

Hemostasis is triggered by a protein called collagen, which is present in the walls of the blood vessels. It is normally isolated from direct contact with the blood by internal endothelium. However, if a blood vessel wall is damaged by an injury or contusion, collagen comes into contact with the blood, whereby hemostasis is induced so as to minimize blood loss. The activation of hemostasis by Hypro-Sorb O drying triangles occurs in a heterogeneous system consisting of a liquid phase – blood – and a solid phase – atelocollagen. The rate, or reaction kinetics, of such reactions is mainly determined by the interface area, i.e., the surface area of the solid phase which is in contact with the liquid. The larger this interface area is, the faster the process of stopping the bleeding is activated. The interface area is determined by what is called the internal area of the solid phase and also by the moistening ability of the liquid in contact with it. Thus, the porosity and hydrophilic nature of the surface are very important, not only pertaining to the drying process but also regarding hemostasis. Atelocollagen is a protein that is naturally hydrophilic. Enormously large internal surface areas in Hypro-Sorb O drying materials are achieved by lyophilization. During the initial phase of blood coagulation, fibrinogen is hydrolyzed enzymatically and fibers of fibrin are formed. The fibers form agglomerates under the effect of the surface charge, forming soft coagulate. This is converted to hard coagulate by crosslinking under the effect of transglutaminase FXIIIa, which forms new amidic bonds. Serine proteinase, which catalyzes fibrinogen hydrolysis, is called thrombin. It is released from its precursor, prothrombin, on the action of another proteinase whose activity is controlled by the factor FVIII complex.



Figure. Scheme of the formation of soft coagulate and interactions of factors during atelocollagen-activated hemostasis. Courtesy of Lars Faxälv, www.haemostasis.se. The figure has been modified.

How is Hypro-Sorb O used?

Hypro-Sorb O is applied to the bleeding surface and compressed slightly. Hypro-Sorb O is most efficient when dry. In fact, it can be moistened with blood or saline to facilitate shaping; however, its absorbing capacity during drying is thereby reduced. The use of a sponge or Hypro-Sorb R hemostatic felt in combination with Hypro-Sorb O is advisable when larger volumes of liquids and/or blood are to be absorbed.

Comparison of hemostatic efficiency

Diagram of the hemostatic efficiency for materials used for drying in ophthalmology and neurosurgery.

In what amount of time is the material resorbed by the tissue?

Hypro-Sorb O can be left in the wound after surgery, if necessary. It is recommended that the surgeon (at his/her own discretion) remove excessive felt before closing the wound. Tests have revealed that Hypro-Sorb O will be resorbed completely within 2 to 4 weeks of implantation.

Hypro-Sorb O sizes