Welcome To Medira Ltd

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Medira Ltd specialises in collagen biomaterials, and is delighted to bring you unique and highly effective products for wound healing and reconstruction.

"I have found these dressings to be fantastic. They have certainly saved our clinic money. When all other treatments had failed, these finally healed wounds." DL, dressings clinic nurse

"I confirm that in more than 30 years experience, Helisorb Particles showed the most remarkable result in a non-healing wound that I have seen." Mr DS, FRCS

 "I am extremely impressed with results to date. My first patient had extensive non-healing donor sites that showed epithelialisation in 7 days after using Neuskin-F." GL, CNS

"Collagen dressings do many things that an advanced wound dressing cannot. Particularly as it relates to stimulation of chemotaxis, mitosis and angiogenesis"  (Landsman et al. 2009)

Collagen biomaterials play an active role in facilitating wound healing.

Why are collagen dressings so effective when used in wound healing?

• Collagen dressings play a unique and key role in each phase of wound healing.
• Collagen is a natural substrate for cellular attachment, growth and differentiation

Healing is uniquely facilitated because exogenous collagen dressings directly interact with the complex cellular sequence of events that take place during every phase of healing.

Upon injury, a series of biochemical events are initiated. These wound healing activities are generally grouped into 4 overlapping phases:

• Hemostasis
• Inflammation
• Proliferation
• Remodeling.

Collagen involvement occurs right from the first phase in wound healing.   
During hemostasis blood platelets will immediately bind to exogenous collagen, initiating the body’s natural coagulation cascade.

Collagen has been identified as having multiple functions in the wound healing process.
(Advances in Skin & Wound Care: The Journal for Prevention and Healing. August 2008 Volume 21 Number 8 Pages 370 – 374)

Primarily, exogenous collagen possesses the following properties.

(1) Hemostasis: collagen binds to fibronectin,^1,2 causing platelet adhesion and aggregation³ .
(2) Autolysis: it has the propensity to chemotactically attract monocytes and leukocytes^4,5 .
(3) Angiogenesis: collagen attracts monocytes^4,5,which transform into macrophages⁶ These macrophages release substances that result in fibroplasia and angiogenesis⁷.  Collagen provides support for the growth of new capillaries^7,8. The presence of new capillaries is essential for the deposition of new fibers⁷.
(4) Fibroblastosis activity: collagen binds with fibronectin^1,2 which promotes cell binding^9,10. Collagen is chemotactic to fibroblasts¹¹ which govern the restoration of new tissue¹² by depositing oriented and organized fibers^13,14.
(5) Reepithelialization: collagen directly supports the growth^15,16,attachment¹⁷, differentiation^16,17 and migration¹⁸ of keratinocytes.


REFERENCES

1. Termine JD, Belcourt AB, Conn KM, Kleinman HK. Mineral and collagen-binding proteins of fetal calf bone. J Biol Chem 1981;256(20):10403-8.
2. Mosher DF, Schad PE. Cross-linking of fibronectin to collagen by blood coagulation factor XIIIa. J Clin Invest 1979;64:781-7.
3. Yamada KM, Olden K. Fibronectins-adhesive glycoproteins of cell surface and blood. Nature 1978;275(5677):179-84.
4. Postlethwaite AE, Seyer JM, Kang AH. Chemotactic attraction of human fibroblasts to type I, II, and III collagens and collagen-derived peptides. Proc Natl Acad Sci USA 1978;75:871-5.
5. Postlethwaite AE, Kang AH. Collagen- and collagen peptide-induced chemotaxis of human blood monocytes. J Exp Med 1976;143(6):1299-307
6. Bryant R. Wound repair: a review. J Enterostomal Ther 1987;14:262-6.
7. Gogia PP. The biology of wound healing. Ostomy Wound Manage 1992;38(9):12, 14-6, 18-22
8. Schor AM, Schor SL, Kumar S. Importance of a collagen substratum for stimulation of capillary endothelial cell proliferation by tumour angiogenesis factor. Int J Cancer 1979;24:225-34
9. Yamada KM, Yamada SS, Pastan I. Cell surface protein partially restores morphology, adhesiveness, and contact inhibition of movement to transformed fibroblasts. Proc Natl Acad Sci USA 1976;73(4):1217-21
10. Mosher DF. Fibronectin. Prog Hemost Thromb 1980;5:111-51
11. Chiang TM, Postlethwaite AE, Beachey EH, Seyer JM, Kang AH. Binding of chemotactic collagen-derived peptides to fibroblasts. The relationship to fibroblast chemotaxis. J Clin Invest 1978;62:916-22.
12. Ross R. The fibroblast and wound repair. Biol Rev Camb Philos Soc 1968;43(1):51-98. 13. Dunn GA, Ebendal T. Contact guidance on oriented collagen gels. Exp Cell Res 1978;111:475-9
14. Tomaseck JT, Hay ED, Fujiwara K. Collagen modulates are shape and cytoskeleton of embryonic corneal and fibroma fibroblasts: distribution of actin, alpha-actin, and myosin. Dev Biol 1982;92(1):107-22.
15. Morykwas MJ, Stevenson TR, Marcelo CL, Thornton JW, Smith DJ Jr. In vitro and in vivo testing of a collagen sheet to support keratinocyte growth for use as a burn wound covering. J Trauma 1989;29:1163-7.
16. Karasek MA. Growth and differentiation of transplanted epithelial cell cultures. J Invest Dermatol 1968;51(4):247-52.
17. Murray JC, Stingl G, Kleinman HK, Martin GR, Katz SI. Epidermal cells adhere preferentially to type IV (basement membrane) collagen. J Cell Biol 1979;80:197-202.
18. Emerman JT, Pitelka DR. Maintenance and induction of morphological differentiation in dissociated mammary epithelium on floating collagen membranes. In Vitro 1977;13(5):316-28.