Using Bioactive Glass Scaffolding to Accelerate Vascular Regeneration

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Considerable developments in the scaffolds available for use in tissue engineering have made vascularization — the provision of a sufficient blood vessel system — a major limitation in the regeneration of tissues following trauma.²

As a result, a number of methods have been employed to obtain the required vascularization so that adequate blood can be supplied to bioengineered tissue. In these methods, the scaffold is loaded with angiogenic growth factors, such as endothelial cells, vascular endothelial cell growth factor (VEGF), and even prevascularization of the tissue that needs to be implanted.²

It has been shown that bioactive glasses offer scaffolds that are effective for soft tissue engineering¹. These scaffolds are strong, lightweight and biocompatible, and can be developed to degrade at a rate that corresponds with the new tissue growth.¹ It has become obvious in recent years that angiogenesis is promoted by bioactive glass which is critical for supporting the growth of new tissues.

This article explores how vascular regeneration is improved by bioactive glass.

Tissue Engineering After Trauma

The human body has a remarkable ability to heal itself after undergoing trauma, but this type of healing is known to be a complicated biological process that needs a lot of different cell types in order to complete the required steps at the right time.³ When there is a huge loss of tissue, tissue engineering is used to create a temporary biomaterial scaffold, which gives the required shape or support during the growth of new tissues.

Blood vessels that are damaged should initially constrict in order to reduce blood loss, but these are required to regenerate so that necessary nutrients can be provided to the new tissue that was produced to restore the damage. Therefore, vascular regeneration plays a crucial role in the healing process. If there is not an adequate vascular system, the nutrients required for growth cannot be supplied.

Bioactive glass, with respect to its strength, biocompatibility and a host of achievable properties, is extensively utilized to provide the much-needed support in tissue engineering and has been used effectively in cartilage repair as well as in the repair of soft tissue and bone.¹ After the bioactive glass is implanted in the body, reactions place on its surface that enable bonding with the existing tissue. Bioactive glass can also release ions, for example calcium that is critical for skin and bone regeneration is required to support regeneration and encourage rapid formation of bones.⁴ It has also become obvious recently that vascularization can be promoted by bioactive glass – with no growth factors added to the scaffold.^5-7

Bioactive Glass can Accelerate Healing

In tissue engineering, bioactive glass is a valuable tool. Initially applied to promote bone repair, bioactive glass also provides remarkable benefits when included as a part of bioscaffold materials that are used in the repair of soft tissues. Another benefit of bioactive glass, in addition to speeding up the healing process, is that its rate of resorption can be customized to meet a specific repair requirement.¹ In wound healing, a new form of borate bioactive glass has been effectively employed.⁸

A scaffold, formed by a fibrous network of glass fibers rich in calcium, promotes regeneration of skin. In patients who had diabetic ulcers and were at risk of limb amputation, the use of this bioactive glass completely repaired the skin in nearly two thirds of cases in just a few months with little to no scarring.⁸

It has been shown recently that tissue regeneration is actively improved by bioactive glass, which stimulates the secretion of angiogenic growth factors. These growth factors not only encourage the proliferation of microvascular endothelial cells but also improve revasularization^5,6. Therefore, bioactive glass has the potential to improve an important process in tissue regeneration⁷, enabling tissue repair more quickly without having to add recombinant inductive growth factors.

Conclusion

Established as an indispensable tool in various tissue engineering applications, bioactive glass promotes bone and soft tissue repair and at the same time also gives structural support. Bioactive glass can also be engineered in such a way that it lasts just as long as is required for the new tissue to develop and grow and achieve the required strength and volume for the repair to be completed.

It has also been demonstrated that bioactive glass increased the levels of angiogenic growth factor, which accelerated vascular regeneration. Since blood vessels are needed to provide the required nutrients for the development and growth of new tissue, vascularization plays an important role in tissue repair.

In the past, the development of new blood vessels was promoted by adding recombinant growth factors to tissue engineering scaffolds. Now, this additional process can be eliminated by using bioactive glass in the scaffold material.

Therefore, proangiogenic potential is another preferred quality that can be introduced to the characteristics of bioactive glass, further supporting the usage of bioactive glass in temporary healing scaffolds during tissue engineering procedures.

Mo-Sci produces medical implant grade bioactive glass in a variety of formats that can be used in various tissue engineering scaffolds. The company can also customize the composition of the bioactive glass to meet particular requirements.⁹

References

1. Rahaman MN, Day DE, Bal S, et al. Bioactive glass in tissue engineering. Acta Biomaterialia 2011;7:2355 2373.
2. Baiguera S and Ribatti D. Endothelialization approaches for viable engineered tissues. Angiogenesis. 2013 Jan;16(1):1 14.
3. Guo S, and DiPietro LA. Factors Affecting Wound Healing. J Dent Res. 2010;89(3): 219–229.
4. Gerhardt L-C and Boccaccini AR. Bioactive Glass and Glass-Ceramic Scaffolds for Bone Tissue Engineering. Materials 2010;3:3867 3910.
5. Day RM, et al. Bioactive glass stimulates the secretion of angiogenic growth factors and angiogenesis in vitro. Tissue Eng. 2005 May-Jun;11(5-6):768 77.
6. Leu A and Leach JK. Proangiogenic Potential of a Collagen/Bioactive Glass Substrate. Pharmaceutical Research 2008;25 (5):1222–1229.
7. Gorustovich A, et al. Effect of bioactive glasses on angiogenesis: In-vitro and in-vivo evidence: A review. Tissue Eng. Part B Rev. 2010;16:199 207.
8. The American Ceramic Society Press release 4 May 2011. Available at https://www.sciencedaily.com/releases/2011/05/110503133056.htm
9. Mo Sci website. http://www.mo-sci.com/

About Mo-Sci

Mo-Sci, a world leader in precision glass technology, explores and develops new and exciting ways for their products and services to integrate within a wide variety of useful applications.

Mo-Sci has become a world leader in the research, development and manufacturing of glasses for specialty applications.

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