Biomedical applications of polyglycolic acid (PGA)
Year 2017,
, 1237 - 1244, 01.12.2017
Ersen Göktürk
,
Hüseyin Erdal
Abstract
Biodegradable polymers have a great potential and widely
used in biomedical applications due to their biodegradability and
biocompatibility. Biodegradable polymers contain hydrolytically unstable
functional groups (such as esters, anhydrides and etc.) in their backbone.
These hydrolytically unstable functional groups can be hydrolyzed, or eaten by
microorganisms, and degradability happens. Biodegradable polymers can be
effectively used for several biomedical applications such as drug delivery,
dental, orthopedic and tissue engineering. Polyglycolic acid (PGA) is a desired
material for physicians due to its excellent degradation behaviour. However,
limited research based on PGA polymers has been studied in biomedical
applications due to insolubility of PGA in most of the solvents and rapid
degradation of PGA. This review will focus on the improvements made in the
development of hydrolytically degradable PGA in biomedical fields.
References
- 1. M. Kolybaba, L. G. Tabil, S. Panigrahi, W. J. Crerar, T. Powell, and B. Wang. (2003). Biodegradable Polymers: Past, Present, and Future. Presented at the American Society of Agricultural Engineers (ASAE), Paper Number: RRV03-0007. [online]. Available:http://www.biodeg.net/fichiers/Biodegradable%20Polymers%20Past,%20Present,%20and%20Future%20(Eng).pdf.
- 2. C. K. Williams. (13 July 2007). Synthesis of functionalized biodegradable polyesters. Chem. Soc. Rev. [online]. 36, pp.1573–1580. Available: http://pubs.rsc.org/en/Content/ArticleLanding/2007/CS/b614342n#!divAbstract.
- 3. N. Lucas, C. Bienaime, C. Belloy, M. Queneudec, F. Silvestre, and J. E. Nava-Saucedo. (September 2008). Polymer biodegradation: mechanisms and estimation techniques. Chemosphere. [online]. 73(4), pp. 429–442. Available: http://www.sciencedirect.com/science/article/pii/S0045653508008333.
- 4. E. Piskin. (1995). Biodegradable polymers as biomaterials. J. Biomater. Sci. Polym. Ed. [online]. 6(9), pp. 775-795. Available: http://www.tandfonline.com/doi/abs/10.1163/156856295X00175?journalCode=tbsp20.
- 5. V. Singh and M. Tiwari. (25 September 2010). Structure-Processing-Property Relationship of Poly(Glycolic Acid) for Drug Delivery Systems 1:Synthesis and Catalysis. Int. J. of Polym. Sci. [online]. Article ID 652719:23 pages. Available: https://www.hindawi.com/journals/ijps/2010/652719/.
- 6. B. D. Ulery, L. S. Nair, and C. T. Laurencin. (15 June 2011). Biomedical applications of biodegradable polymers. Journal of Polymer Science Part B: Polymer Physics. [online]. 49(12), pp. 832–864. Available: http://onlinelibrary.wiley.com/doi/10.1002/polb.22259/abstract.
- 7. A. W. Lloyd. (February 2002). Interfacial bioengineering to enhance surface biocompatibility. Med. Device Technol. [online]. 13(1), pp. 18–21. Available: https://www.ncbi.nlm.nih.gov/pubmed/11921776.
- 8. I. Vroman and L. Tighzert. (1 April 2009). Biodegradable Polymers. Materials. [online]. 2(2), pp. 307-344. doi:10.3390/ma2020307. Available: http://www.mdpi.com/1996-1944/2/2/307.
- 9. J. Middleton and A. Tipton. (1 March 1998). Synthetic biodegradable polymers as medical devices. MDDI medical device and diagnostic industry news products and suppliers. [online]. Available: http://www.mddionline.com/article/synthetic-biodegradable-polymers-medical-devices.
- 10. E. Göktürk, A. G. Pemba, and S. A. Miller. (28 April 2015). Polyglycolic acid from the direct polymerization of renewable C1 feedstocks. Polym. Chem. [online]. 6, pp. 3918–3925. Available: http://pubs.rsc.org/en/Content/ArticleLanding/2015/PY/c5py00230c#!divAbstract.
- 11. P. Dobrzynski, J. Kasperczyk, and B. Maciej. (18 June 1999). Application of Calcium Acetylacetonate to the Polymerization of Glycolide and Copolymerization of Glycolide with ε–Caprolactone and L-Lactide. Macromolecules. [online]. 32(14), pp. 4735–4737. Available: http://pubs.acs.org/doi/abs/10.1021/ma981969z.
- 12. E. J. Frazza and E. E. Schmitt. (March 1971). A new absorbable suture. J. Biomed. Mater. Res. [online]. 5(2), pp. 43-58. Available: http://onlinelibrary.wiley.com/doi/10.1002/jbm.820050207/abstract.
- 13. A. R. Katz and R. J. Turner. (October 1970). Evaluation of tensile and absorption properties of polyglycolic acid sutures. Surg. Gynecol. Obstet. [online]. 131(4), pp. 701–716. Available: https://www.ncbi.nlm.nih.gov/pubmed/5458531.
- 14. Kuredux Polyglycolic Acid (PGA) Resin, A New Polymer Option, [online]. Available: http://www.kureha.com/product-groups/pga.htm.
- 15. E. E. Schmitt and R. A. Polistina. (10 January 1967). Surgical sutures. US patent 3,297,033. [online]. Available: https://docs.google.com/viewer?url=patentimages.storage.googleapis.com/pdfs/US3297033.pdf.
- 16. S. W. Shalaby and R. A. Johnson, “Synthetic absorbable polyesters”, Biomedical polymers: Designed to degrade systems, S. W. Shalaby, Ed. New York: Hanser, 1994, pp.1-34.
- 17. J. Fu, J. Fiegel and J. Hanes. (25 August 2004). Synthesis and Characterization of PEG-Based Ether−Anhydride Terpolymers: Novel Polymers for Controlled Drug Delivery. Macromolecules. [online]. 37(19), pp. 7174–7180. Available: http://pubs.acs.org/doi/abs/10.1021/ma049853s.
- 18. O. Bostman, E. Hirvensalo, S. Vainionpaa, A. Makela, K. Vihtonen, P. Tormala, and P. Rokkanen. (January 1989). Ankle fractures treated using biodegradable internal fixation. Clin. Orthop. Related Res. [online]. 238, pp. 195-203. Available: http://journals.lww.com/corr/Abstract/1989/01000/Ankle_Fractures_Treated_Using_Biodegradable.28.aspx.
- 19. O. Bostman, E. Hirvensalo, S. Vainionpaa, K. Vihtonen, P. Tormala, and P. Rokkanen. (1990). Degradable polyglycolide rods for the internal fixation of displaced bimalleolar fractures. Int. Orthop. (SICOT). [online]. 14(1), pp: 1-8. Available: https://www.ncbi.nlm.nih.gov/pubmed/2160439.
- 20. E. Hirvensalo. (October 1989). Fracture fixation with biodegradable rods. Forty-one cases of severe ankle fractures. Acta Orthop. Stand. [online]. 60(5), pp. 601-606. Available: https://www.ncbi.nlm.nih.gov/pubmed/2557718.
- 21. O. Bostman, E. Hirvensalo, J. Makinen, and P. Rokkanen. (July 1990). Foreign-body reactions to fracture fixation implants of biodegradable synthetic polymers. J Bone Joint Surg. [online]. 72(4), pp. 592-596. Available: http://www.bjj.boneandjoint.org.uk/content/jbjsbr/72-B/4/592.full.pdf.
- 22. K. A. Athanasiou, G. G. Niederauer, and C. M. Agrawal. (January 1996). Sterilization, toxicity, biocompatibility and clinical applications of polylactic acid/ polyglycolic acid copolymers. Biomoterials. [online]. 17(2), pp. 93-102. Available: http://www.sciencedirect.com/science/article/pii/0142961296857541.
- 23. B. K. Behera. (25 November 2013). Pharmaceutical Applications of Lactides and Glycolides: A Review. Journal of Medical and Pharmaceutical Innovation. [online]. 1(1), pp. 1-5. Available: http://www.jmedpharm.com/index.php?journal=JMPI&page=article&op=view&path%5B%5D=4.
- 24. D. Gilding and A. M. Reed. (December 1979). Biodegradable polymers for use in surgery-polyglycolic/poly(lactic acid) homo- and copolymers: 1. Polymer. [online]. 20(12), pp. 1459-1464. Available: http://www.sciencedirect.com/science/article/pii/0032386179900090.
- 25. I. P. Matthews, C. Gibson, and A. H. Samuel. (13 September 1989). Enhancement of the kinetics of the aeration of ethylene oxide sterilized polymers using microwave radiation. J. Biomed. Mater. Res. [online]. 23(2), pp. 143-156. Available: http://onlinelibrary.wiley.com/doi/10.1002/jbm.820230202/pdf.
- 26. Y. Chen, L. Tan, L. Chen, Y. Yang, and X. Wang. (June 2008). Study on Biodegradable Aromatic/Aliphatic Copolyesters. Brazilian Journal of Chemical Engineering. [online]. 25(02), pp. 321-335. Available: http://www.scielo.br/pdf/bjce/v25n2/a11v25n2.pdf.
- 27. S. D. Andrew, G. C. Phil, and K. G. Marra. (August 2001). The influence of polymer blend composition on the degradation of polymer/hydroxyapatite biomaterials. J. Mater. Sci: Mater. Med. [online]. 12(8), pp. 673–677. Available: http://link.springer.com/article/10.1023/A:1011204106373.
- 28. W. Heidemann, S. Jeschkeit, K. Ruffieux, J. H. Fischer, M. Wagner, G. Kruger, and et al. (September 2001). Degradation of poly(D,L)lactide implants with or without addition of calciumphosphates in vivo. Biomaterials. [online]. 22(17), pp. 2371–2381. Available: https://www.ncbi.nlm.nih.gov/pubmed/11511034.
- 29. J. C. Middleton and A. J. Tipton. (1 December 2000). Synthetic biodegradable polymers as orthopedic devices. Biomaterials. [online]. 21(23), pp. 2335-2346. Available: http://www.sciencedirect.com/science/article/pii/S0142961200001010.
- 30. J. R. Fuchs, B. A. Nasseri, and J. P. Vacanti. (August 2001). Tissue engineering: a 21st century solution to surgical reconstruction. Ann Thorac Surg. [online]. 72(2), pp. 577-591. Available: http://www.sciencedirect.com/science/article/pii/S000349750102820X.
- 31. A. Persidis. (1999). Tissue engineering. Nat. Biotechnol. [online]. 17(5), pp. 508-510. Available: http://www.nature.com/nbt/journal/v17/n5/full/nbt0599_508.html.
- 32. L. G. Griffith and G. Naughton. (08 February 2002). Tissue engineering—current challenges and expanding opportunities. Science. [online]. 295(5557), pp. 1009-1014. Available: http://science.sciencemag.org/content/295/5557/1009.full.
- 33. L. G. Cima, J. P. Vacanti, C. Vacanti, D. Ingber, D. Mooney, and R. Langer. (1 May 1991). Tissue engineering by cell transplantation using degradable polymer substrates. J. Biomech. Eng. [online]. 113(2), pp. 143-151. Available: http://biomechanical.asmedigitalcollection.asme.org/article.aspx?articleid=1398574.
- 34. A. G. Mikos, Y. Bao, L. G. Cima, D. E. Ingber, J. P. Vacanti, and R. Langer. (September 1993). Preparation of poly(glycolic acid) bonded fiber structures for cell attachment and transplantation. J. Biomed. Mater. Res. [online]. 27(2), pp. 183-189. Available: http://onlinelibrary.wiley.com/doi/10.1002/jbm.820270207/pdf.
- 35. K. Rezwana, Q. Z. Chena, J. J. Blakera, and A. R. Boccaccinia. (June 2006). Biodegradable and bioactive porous polymer/inorganic composite scaffolds for bone tissue engineering. Biomaterials. [online]. 27(18), pp. 3413–3431. Available: http://www.sciencedirect.com/science/article/pii/S0142961206001232.
- 36. S. Joji, H. Muneshige, and Y. Ikuta. (October 1999). Experimental study of mechanical microvascular anastomosis with new biodegradable ring device. British Journal of Plastic Surgery. [online]. 52(7), pp. 559–564. Available: http://www.sciencedirect.com/science/article/pii/S0007122699931314.
- 37. E. L. Chaikof, H. Matthew, J. Kohn, A. G. Mikos, G. D. Prestwich, and C. M. Yip. (June 2002). Biomaterials and scaffolds in reparative medicine. Ann NY Acad Sci. [online]. 961, pp. 96–105. Available: http://onlinelibrary.wiley.com/doi/10.1111/j.1749-6632.2002.tb03057.x/abstract.
- 38. O. C. Farokhzad, J. D. Dimitrakov, J. M. Karp, A. Khademhosseini, M. R. Freeman, and R. Langer. (September 2006). Drug Delivery Systems in Urology-Getting “Smarter”. Urology. [online]. 68(3), pp. 463–469. doi:10.1016/j.urology.2006.03.069. Available: http://www.sciencedirect.com/science/article/pii/S0090429506004997.
- 39. A. J. Gavasane and H. A. Pawar. (22 September 2014). Synthetic Biodegradable Polymers Used in Controlled Drug Delivery System: An Overview. Clinical Pharmacology & Biopharmaceutics. [online]. 3(2), pp. 1-7. Available: https://www.omicsgroup.org/journals/synthetic-biodegradable-polymers-used-in-controlled-drug-delivery-system-2167-065X.1000121.php?aid=31480.
- 40. V. B. Kotwal, M. Saifee, N. Inamdar, and K. Bhise. (2007). Biodegradable polymers: Which, when and why?. Indian Journal of Pharmaceutical Sciences. [online]. 69(5), pp. 616-625. Available: http://www.ijpsonline.com/articles/biodegradable-polymers-which-when-and-why.html.
- 41. R. Langer. (30 April 1998). Drug delivery and targeting. Nature. [online]. 392(6679), pp. 5-10. Available: https://www.ncbi.nlm.nih.gov/pubmed/9579855.
- 42. H. Rosen and T. Abribat. (May 2005). The rise and rise of drug delivery. Nat. Rev. Drug Discov. [online]. 4, pp. 381-385. Available: http://www.nature.com/nrd/journal/v4/n5/full/nrd1721.html.
- 43. J. H. Park, M. G. Allen, and M. R. Prausnitz. (May 2006). Polymer Microneedles for controlled-release drug delivery. Pharmaceutical Research. [online]. 23(5), pp. 1008-1019. Doi:10.1007/s11095-006-0028-9. Available: http://link.springer.com/article/10.1007%2Fs11095-006-0028-9.
- 44. S. Kempe, H. Metz, and K. Mäder. (24 September 2008). Do in situ forming PLG/NMP implants behave similar in vitro and in vivo? A non-invasive and quantitative EPR investigation on the mechanisms of the implant formation process. Journal of Controlled Release. [online]. 130(3), pp. 220–225. Available: http://www.sciencedirect.com/science/article/pii/S0168365908003386.
- 45. M. R. Shaik, M. Korsapati, and D. Panati. (24 November 2012). Polymers in Controlled Drug Delivery Systems. International Journal of Pharma Sciences. [online]. 2(4), pp. 112-116. Available: http://ijps.aizeonpublishers.net/content/2012/4/ijps112-116.pdf.
- 46. M. D. T. Yasukawa, H. Kimurab, Y. Tabatac, and Y. Ogurab. (31 October 2001). Biodegradable scleral plugs for vitreoretinal drug delivery. Advanced Drug Delivery Reviews. [online]. 52(1), pp. 25–36. Available: http://www.sciencedirect.com/science/article/pii/S0169409X01001922.
- 47. C. G. Pitt, M. M. Gratzl, A. R. Jeffcoat, R. Zweidinger, and A. Schindler. (December 1979). Sustained drug delivery systems. II. Factors affecting release rates from poly(e-caprolactone) and related biodegradable polymers. J. Pharm. Sci. [online]. 68(12), pp. 1534–1538. Available: http://www.sciencedirect.com/science/article/pii/S0022354915429557.
- 48. M. S. Hora, R. K. Rana, J. H. Nunberg, T. R. Tice, R. M. Gilley, and M. E. Hudson. (November 1990). Release of human serum albumin from poly(lactide-co-glycolide) microspheres. Pharm. Res. [online]. 7(11), pp. 1190–1194. Available: http://link.springer.com/article/10.1023/A:1015948829632.
- 49. L. M. Sanders, J. S. Kent, G. I. Mcrae, B. H. Vickery, T. R. Tice, and D. H. Lewis. (September 1984). Controlled release of a luteinizing hormone-releasing hormone analogue from poly(D,L-lactide-co-glycolide) microspheres. J. Pharm. Sci. [online]. 73(9), pp. 1294–1297. Available: http://www.sciencedirect.com/science/article/pii/S0022354915463154.
- 50. D. A. Wood. (November 1980). Biodegradable drug delivery systems. International Journal of Pharmaceutics. [online]. 7(1), pp. 1-18. Available: http://www.sciencedirect.com/science/article/pii/0378517380900940.
Poliglikolik Asit’ in (PGA) Biyomedikal uygulamaları
Year 2017,
, 1237 - 1244, 01.12.2017
Ersen Göktürk
,
Hüseyin Erdal
Abstract
Biyobozunur
polimerler, biyobozunurluk ve biyouyumluluk özelliklerinden dolayı biyomedikal uygulamalarda
büyük potansiyele sahip olup yaygın şekilde kullanılmaktadır. Biyobozunur
polimerler yapılarında hidrolitik olarak kararsız fonksiyonel gruplar (örneğin,
esterler, anhidritler vd.) içerirler. Bu hidrolitik olarak kararsız gruplar
kolayca hidroliz olabilmekte, veya mikroorganizmalar tarafından
yenilebilmektedir. Bu sayede polimerlerin bozunması gerçekleşir. Biyobozunur
polimerler birçok biyomedikal alanda (örneğin; ilaç salınımı, dişçilik,
ortopedi, ve doku mühendisliği) etkili bir biçimde kullanılabilmektedir.
Poliglikolik asit (PGA) oldukça iyi bozunma davranışından dolayı tıp alanında
yaygın şekilde kullanılan bir materyaldir. Ancak, PGA polimerlerinin
biyomedikal uygulamaları alanında sınırlı sayıda araştırma mevcuttur. PGA
birçok çözücü içerisinde çözünememekte ve hızlı bir şekilde bozunmaya
uğramaktadır. Bu derleme hidrolitik olarak bozunabilen PGA’ nın biyomedikal
alanda kullanımındaki yenilikleri açıklayacaktır.
References
- 1. M. Kolybaba, L. G. Tabil, S. Panigrahi, W. J. Crerar, T. Powell, and B. Wang. (2003). Biodegradable Polymers: Past, Present, and Future. Presented at the American Society of Agricultural Engineers (ASAE), Paper Number: RRV03-0007. [online]. Available:http://www.biodeg.net/fichiers/Biodegradable%20Polymers%20Past,%20Present,%20and%20Future%20(Eng).pdf.
- 2. C. K. Williams. (13 July 2007). Synthesis of functionalized biodegradable polyesters. Chem. Soc. Rev. [online]. 36, pp.1573–1580. Available: http://pubs.rsc.org/en/Content/ArticleLanding/2007/CS/b614342n#!divAbstract.
- 3. N. Lucas, C. Bienaime, C. Belloy, M. Queneudec, F. Silvestre, and J. E. Nava-Saucedo. (September 2008). Polymer biodegradation: mechanisms and estimation techniques. Chemosphere. [online]. 73(4), pp. 429–442. Available: http://www.sciencedirect.com/science/article/pii/S0045653508008333.
- 4. E. Piskin. (1995). Biodegradable polymers as biomaterials. J. Biomater. Sci. Polym. Ed. [online]. 6(9), pp. 775-795. Available: http://www.tandfonline.com/doi/abs/10.1163/156856295X00175?journalCode=tbsp20.
- 5. V. Singh and M. Tiwari. (25 September 2010). Structure-Processing-Property Relationship of Poly(Glycolic Acid) for Drug Delivery Systems 1:Synthesis and Catalysis. Int. J. of Polym. Sci. [online]. Article ID 652719:23 pages. Available: https://www.hindawi.com/journals/ijps/2010/652719/.
- 6. B. D. Ulery, L. S. Nair, and C. T. Laurencin. (15 June 2011). Biomedical applications of biodegradable polymers. Journal of Polymer Science Part B: Polymer Physics. [online]. 49(12), pp. 832–864. Available: http://onlinelibrary.wiley.com/doi/10.1002/polb.22259/abstract.
- 7. A. W. Lloyd. (February 2002). Interfacial bioengineering to enhance surface biocompatibility. Med. Device Technol. [online]. 13(1), pp. 18–21. Available: https://www.ncbi.nlm.nih.gov/pubmed/11921776.
- 8. I. Vroman and L. Tighzert. (1 April 2009). Biodegradable Polymers. Materials. [online]. 2(2), pp. 307-344. doi:10.3390/ma2020307. Available: http://www.mdpi.com/1996-1944/2/2/307.
- 9. J. Middleton and A. Tipton. (1 March 1998). Synthetic biodegradable polymers as medical devices. MDDI medical device and diagnostic industry news products and suppliers. [online]. Available: http://www.mddionline.com/article/synthetic-biodegradable-polymers-medical-devices.
- 10. E. Göktürk, A. G. Pemba, and S. A. Miller. (28 April 2015). Polyglycolic acid from the direct polymerization of renewable C1 feedstocks. Polym. Chem. [online]. 6, pp. 3918–3925. Available: http://pubs.rsc.org/en/Content/ArticleLanding/2015/PY/c5py00230c#!divAbstract.
- 11. P. Dobrzynski, J. Kasperczyk, and B. Maciej. (18 June 1999). Application of Calcium Acetylacetonate to the Polymerization of Glycolide and Copolymerization of Glycolide with ε–Caprolactone and L-Lactide. Macromolecules. [online]. 32(14), pp. 4735–4737. Available: http://pubs.acs.org/doi/abs/10.1021/ma981969z.
- 12. E. J. Frazza and E. E. Schmitt. (March 1971). A new absorbable suture. J. Biomed. Mater. Res. [online]. 5(2), pp. 43-58. Available: http://onlinelibrary.wiley.com/doi/10.1002/jbm.820050207/abstract.
- 13. A. R. Katz and R. J. Turner. (October 1970). Evaluation of tensile and absorption properties of polyglycolic acid sutures. Surg. Gynecol. Obstet. [online]. 131(4), pp. 701–716. Available: https://www.ncbi.nlm.nih.gov/pubmed/5458531.
- 14. Kuredux Polyglycolic Acid (PGA) Resin, A New Polymer Option, [online]. Available: http://www.kureha.com/product-groups/pga.htm.
- 15. E. E. Schmitt and R. A. Polistina. (10 January 1967). Surgical sutures. US patent 3,297,033. [online]. Available: https://docs.google.com/viewer?url=patentimages.storage.googleapis.com/pdfs/US3297033.pdf.
- 16. S. W. Shalaby and R. A. Johnson, “Synthetic absorbable polyesters”, Biomedical polymers: Designed to degrade systems, S. W. Shalaby, Ed. New York: Hanser, 1994, pp.1-34.
- 17. J. Fu, J. Fiegel and J. Hanes. (25 August 2004). Synthesis and Characterization of PEG-Based Ether−Anhydride Terpolymers: Novel Polymers for Controlled Drug Delivery. Macromolecules. [online]. 37(19), pp. 7174–7180. Available: http://pubs.acs.org/doi/abs/10.1021/ma049853s.
- 18. O. Bostman, E. Hirvensalo, S. Vainionpaa, A. Makela, K. Vihtonen, P. Tormala, and P. Rokkanen. (January 1989). Ankle fractures treated using biodegradable internal fixation. Clin. Orthop. Related Res. [online]. 238, pp. 195-203. Available: http://journals.lww.com/corr/Abstract/1989/01000/Ankle_Fractures_Treated_Using_Biodegradable.28.aspx.
- 19. O. Bostman, E. Hirvensalo, S. Vainionpaa, K. Vihtonen, P. Tormala, and P. Rokkanen. (1990). Degradable polyglycolide rods for the internal fixation of displaced bimalleolar fractures. Int. Orthop. (SICOT). [online]. 14(1), pp: 1-8. Available: https://www.ncbi.nlm.nih.gov/pubmed/2160439.
- 20. E. Hirvensalo. (October 1989). Fracture fixation with biodegradable rods. Forty-one cases of severe ankle fractures. Acta Orthop. Stand. [online]. 60(5), pp. 601-606. Available: https://www.ncbi.nlm.nih.gov/pubmed/2557718.
- 21. O. Bostman, E. Hirvensalo, J. Makinen, and P. Rokkanen. (July 1990). Foreign-body reactions to fracture fixation implants of biodegradable synthetic polymers. J Bone Joint Surg. [online]. 72(4), pp. 592-596. Available: http://www.bjj.boneandjoint.org.uk/content/jbjsbr/72-B/4/592.full.pdf.
- 22. K. A. Athanasiou, G. G. Niederauer, and C. M. Agrawal. (January 1996). Sterilization, toxicity, biocompatibility and clinical applications of polylactic acid/ polyglycolic acid copolymers. Biomoterials. [online]. 17(2), pp. 93-102. Available: http://www.sciencedirect.com/science/article/pii/0142961296857541.
- 23. B. K. Behera. (25 November 2013). Pharmaceutical Applications of Lactides and Glycolides: A Review. Journal of Medical and Pharmaceutical Innovation. [online]. 1(1), pp. 1-5. Available: http://www.jmedpharm.com/index.php?journal=JMPI&page=article&op=view&path%5B%5D=4.
- 24. D. Gilding and A. M. Reed. (December 1979). Biodegradable polymers for use in surgery-polyglycolic/poly(lactic acid) homo- and copolymers: 1. Polymer. [online]. 20(12), pp. 1459-1464. Available: http://www.sciencedirect.com/science/article/pii/0032386179900090.
- 25. I. P. Matthews, C. Gibson, and A. H. Samuel. (13 September 1989). Enhancement of the kinetics of the aeration of ethylene oxide sterilized polymers using microwave radiation. J. Biomed. Mater. Res. [online]. 23(2), pp. 143-156. Available: http://onlinelibrary.wiley.com/doi/10.1002/jbm.820230202/pdf.
- 26. Y. Chen, L. Tan, L. Chen, Y. Yang, and X. Wang. (June 2008). Study on Biodegradable Aromatic/Aliphatic Copolyesters. Brazilian Journal of Chemical Engineering. [online]. 25(02), pp. 321-335. Available: http://www.scielo.br/pdf/bjce/v25n2/a11v25n2.pdf.
- 27. S. D. Andrew, G. C. Phil, and K. G. Marra. (August 2001). The influence of polymer blend composition on the degradation of polymer/hydroxyapatite biomaterials. J. Mater. Sci: Mater. Med. [online]. 12(8), pp. 673–677. Available: http://link.springer.com/article/10.1023/A:1011204106373.
- 28. W. Heidemann, S. Jeschkeit, K. Ruffieux, J. H. Fischer, M. Wagner, G. Kruger, and et al. (September 2001). Degradation of poly(D,L)lactide implants with or without addition of calciumphosphates in vivo. Biomaterials. [online]. 22(17), pp. 2371–2381. Available: https://www.ncbi.nlm.nih.gov/pubmed/11511034.
- 29. J. C. Middleton and A. J. Tipton. (1 December 2000). Synthetic biodegradable polymers as orthopedic devices. Biomaterials. [online]. 21(23), pp. 2335-2346. Available: http://www.sciencedirect.com/science/article/pii/S0142961200001010.
- 30. J. R. Fuchs, B. A. Nasseri, and J. P. Vacanti. (August 2001). Tissue engineering: a 21st century solution to surgical reconstruction. Ann Thorac Surg. [online]. 72(2), pp. 577-591. Available: http://www.sciencedirect.com/science/article/pii/S000349750102820X.
- 31. A. Persidis. (1999). Tissue engineering. Nat. Biotechnol. [online]. 17(5), pp. 508-510. Available: http://www.nature.com/nbt/journal/v17/n5/full/nbt0599_508.html.
- 32. L. G. Griffith and G. Naughton. (08 February 2002). Tissue engineering—current challenges and expanding opportunities. Science. [online]. 295(5557), pp. 1009-1014. Available: http://science.sciencemag.org/content/295/5557/1009.full.
- 33. L. G. Cima, J. P. Vacanti, C. Vacanti, D. Ingber, D. Mooney, and R. Langer. (1 May 1991). Tissue engineering by cell transplantation using degradable polymer substrates. J. Biomech. Eng. [online]. 113(2), pp. 143-151. Available: http://biomechanical.asmedigitalcollection.asme.org/article.aspx?articleid=1398574.
- 34. A. G. Mikos, Y. Bao, L. G. Cima, D. E. Ingber, J. P. Vacanti, and R. Langer. (September 1993). Preparation of poly(glycolic acid) bonded fiber structures for cell attachment and transplantation. J. Biomed. Mater. Res. [online]. 27(2), pp. 183-189. Available: http://onlinelibrary.wiley.com/doi/10.1002/jbm.820270207/pdf.
- 35. K. Rezwana, Q. Z. Chena, J. J. Blakera, and A. R. Boccaccinia. (June 2006). Biodegradable and bioactive porous polymer/inorganic composite scaffolds for bone tissue engineering. Biomaterials. [online]. 27(18), pp. 3413–3431. Available: http://www.sciencedirect.com/science/article/pii/S0142961206001232.
- 36. S. Joji, H. Muneshige, and Y. Ikuta. (October 1999). Experimental study of mechanical microvascular anastomosis with new biodegradable ring device. British Journal of Plastic Surgery. [online]. 52(7), pp. 559–564. Available: http://www.sciencedirect.com/science/article/pii/S0007122699931314.
- 37. E. L. Chaikof, H. Matthew, J. Kohn, A. G. Mikos, G. D. Prestwich, and C. M. Yip. (June 2002). Biomaterials and scaffolds in reparative medicine. Ann NY Acad Sci. [online]. 961, pp. 96–105. Available: http://onlinelibrary.wiley.com/doi/10.1111/j.1749-6632.2002.tb03057.x/abstract.
- 38. O. C. Farokhzad, J. D. Dimitrakov, J. M. Karp, A. Khademhosseini, M. R. Freeman, and R. Langer. (September 2006). Drug Delivery Systems in Urology-Getting “Smarter”. Urology. [online]. 68(3), pp. 463–469. doi:10.1016/j.urology.2006.03.069. Available: http://www.sciencedirect.com/science/article/pii/S0090429506004997.
- 39. A. J. Gavasane and H. A. Pawar. (22 September 2014). Synthetic Biodegradable Polymers Used in Controlled Drug Delivery System: An Overview. Clinical Pharmacology & Biopharmaceutics. [online]. 3(2), pp. 1-7. Available: https://www.omicsgroup.org/journals/synthetic-biodegradable-polymers-used-in-controlled-drug-delivery-system-2167-065X.1000121.php?aid=31480.
- 40. V. B. Kotwal, M. Saifee, N. Inamdar, and K. Bhise. (2007). Biodegradable polymers: Which, when and why?. Indian Journal of Pharmaceutical Sciences. [online]. 69(5), pp. 616-625. Available: http://www.ijpsonline.com/articles/biodegradable-polymers-which-when-and-why.html.
- 41. R. Langer. (30 April 1998). Drug delivery and targeting. Nature. [online]. 392(6679), pp. 5-10. Available: https://www.ncbi.nlm.nih.gov/pubmed/9579855.
- 42. H. Rosen and T. Abribat. (May 2005). The rise and rise of drug delivery. Nat. Rev. Drug Discov. [online]. 4, pp. 381-385. Available: http://www.nature.com/nrd/journal/v4/n5/full/nrd1721.html.
- 43. J. H. Park, M. G. Allen, and M. R. Prausnitz. (May 2006). Polymer Microneedles for controlled-release drug delivery. Pharmaceutical Research. [online]. 23(5), pp. 1008-1019. Doi:10.1007/s11095-006-0028-9. Available: http://link.springer.com/article/10.1007%2Fs11095-006-0028-9.
- 44. S. Kempe, H. Metz, and K. Mäder. (24 September 2008). Do in situ forming PLG/NMP implants behave similar in vitro and in vivo? A non-invasive and quantitative EPR investigation on the mechanisms of the implant formation process. Journal of Controlled Release. [online]. 130(3), pp. 220–225. Available: http://www.sciencedirect.com/science/article/pii/S0168365908003386.
- 45. M. R. Shaik, M. Korsapati, and D. Panati. (24 November 2012). Polymers in Controlled Drug Delivery Systems. International Journal of Pharma Sciences. [online]. 2(4), pp. 112-116. Available: http://ijps.aizeonpublishers.net/content/2012/4/ijps112-116.pdf.
- 46. M. D. T. Yasukawa, H. Kimurab, Y. Tabatac, and Y. Ogurab. (31 October 2001). Biodegradable scleral plugs for vitreoretinal drug delivery. Advanced Drug Delivery Reviews. [online]. 52(1), pp. 25–36. Available: http://www.sciencedirect.com/science/article/pii/S0169409X01001922.
- 47. C. G. Pitt, M. M. Gratzl, A. R. Jeffcoat, R. Zweidinger, and A. Schindler. (December 1979). Sustained drug delivery systems. II. Factors affecting release rates from poly(e-caprolactone) and related biodegradable polymers. J. Pharm. Sci. [online]. 68(12), pp. 1534–1538. Available: http://www.sciencedirect.com/science/article/pii/S0022354915429557.
- 48. M. S. Hora, R. K. Rana, J. H. Nunberg, T. R. Tice, R. M. Gilley, and M. E. Hudson. (November 1990). Release of human serum albumin from poly(lactide-co-glycolide) microspheres. Pharm. Res. [online]. 7(11), pp. 1190–1194. Available: http://link.springer.com/article/10.1023/A:1015948829632.
- 49. L. M. Sanders, J. S. Kent, G. I. Mcrae, B. H. Vickery, T. R. Tice, and D. H. Lewis. (September 1984). Controlled release of a luteinizing hormone-releasing hormone analogue from poly(D,L-lactide-co-glycolide) microspheres. J. Pharm. Sci. [online]. 73(9), pp. 1294–1297. Available: http://www.sciencedirect.com/science/article/pii/S0022354915463154.
- 50. D. A. Wood. (November 1980). Biodegradable drug delivery systems. International Journal of Pharmaceutics. [online]. 7(1), pp. 1-18. Available: http://www.sciencedirect.com/science/article/pii/0378517380900940.