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Biodegradable polyphosphazene biomaterials for tissue engineering and delivery of therapeutics.

Baillargeon AL, Mequanint K - Biomed Res Int (2014)

Bottom Line: Polyphosphazenes are synthesized through a relatively well-known two-step reaction scheme which involves the substitution of the initial linear precursor with a wide range of nucleophiles.The objective of this review is to discuss the suitability of poly(amino acid ester)phosphazene biomaterials in regard to their unique stimuli responsive properties, tunable degradation rates and mechanical properties, as well as in vitro and in vivo biocompatibility.Lastly, the utility of polyphosphazenes is further extended as they are being employed in blend materials for new applications and as another method of tailoring material properties.

View Article: PubMed Central - PubMed

Affiliation: Graduate Program of Biomedical Engineering, Faculty of Engineering, The University of Western Ontario, London, ON, Canada N6A 5B9.

ABSTRACT
Degradable biomaterials continue to play a major role in tissue engineering and regenerative medicine as well as for delivering therapeutic agents. Although the chemistry of polyphosphazenes has been studied extensively, a systematic review of their applications for a wide range of biomedical applications is lacking. Polyphosphazenes are synthesized through a relatively well-known two-step reaction scheme which involves the substitution of the initial linear precursor with a wide range of nucleophiles. The ease of substitution has led to the development of a broad class of materials that have been studied for numerous biomedical applications including as scaffold materials for tissue engineering and regenerative medicine. The objective of this review is to discuss the suitability of poly(amino acid ester)phosphazene biomaterials in regard to their unique stimuli responsive properties, tunable degradation rates and mechanical properties, as well as in vitro and in vivo biocompatibility. The application of these materials in areas such as tissue engineering and drug delivery is discussed systematically. Lastly, the utility of polyphosphazenes is further extended as they are being employed in blend materials for new applications and as another method of tailoring material properties.

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Structures of various polyphosphazenes including steroidal substituents (2), carbohydrates (3), amino acid esters (4), and side chain-bound amino acid esters (5), to name a few. Adapted from [5] by permission of the Royal Society of Chemistry (http://dx.doi.org/10.1039/B926402G).
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fig1: Structures of various polyphosphazenes including steroidal substituents (2), carbohydrates (3), amino acid esters (4), and side chain-bound amino acid esters (5), to name a few. Adapted from [5] by permission of the Royal Society of Chemistry (http://dx.doi.org/10.1039/B926402G).

Mentions: Sustained research towards new biomaterials for tissue engineering and regenerative medicine applications has led to the utilization of polyphosphazenes as a class of novel materials. Polyphosphazenes are comprised of an inorganic backbone of repeating phosphorus and nitrogen atoms with alternating single and double bonds (Figure 1, Structure 1c) [6, 17–19]. Extending from each of the phosphorus atoms are two organic side chains, which can range from alkoxy and aryloxy substituents to amino acids, giving a large variety of potential polymers [5, 18, 20, 21]. Changing the organic side groups and their ratios, if multiple different side groups are attached to the same polymer backbone, allows substantial tunability of the physical and degradation properties of the material [18, 22, 23]. Therefore, altering the organic substituents can be quite useful in tailoring the mechanical properties and degradation rates of the biomaterial to suit the desired tissue engineering application, such as bone tissue or blood vessels, which require drastically different physical properties [24, 25].


Biodegradable polyphosphazene biomaterials for tissue engineering and delivery of therapeutics.

Baillargeon AL, Mequanint K - Biomed Res Int (2014)

Structures of various polyphosphazenes including steroidal substituents (2), carbohydrates (3), amino acid esters (4), and side chain-bound amino acid esters (5), to name a few. Adapted from [5] by permission of the Royal Society of Chemistry (http://dx.doi.org/10.1039/B926402G).
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4022062&req=5

fig1: Structures of various polyphosphazenes including steroidal substituents (2), carbohydrates (3), amino acid esters (4), and side chain-bound amino acid esters (5), to name a few. Adapted from [5] by permission of the Royal Society of Chemistry (http://dx.doi.org/10.1039/B926402G).
Mentions: Sustained research towards new biomaterials for tissue engineering and regenerative medicine applications has led to the utilization of polyphosphazenes as a class of novel materials. Polyphosphazenes are comprised of an inorganic backbone of repeating phosphorus and nitrogen atoms with alternating single and double bonds (Figure 1, Structure 1c) [6, 17–19]. Extending from each of the phosphorus atoms are two organic side chains, which can range from alkoxy and aryloxy substituents to amino acids, giving a large variety of potential polymers [5, 18, 20, 21]. Changing the organic side groups and their ratios, if multiple different side groups are attached to the same polymer backbone, allows substantial tunability of the physical and degradation properties of the material [18, 22, 23]. Therefore, altering the organic substituents can be quite useful in tailoring the mechanical properties and degradation rates of the biomaterial to suit the desired tissue engineering application, such as bone tissue or blood vessels, which require drastically different physical properties [24, 25].

Bottom Line: Polyphosphazenes are synthesized through a relatively well-known two-step reaction scheme which involves the substitution of the initial linear precursor with a wide range of nucleophiles.The objective of this review is to discuss the suitability of poly(amino acid ester)phosphazene biomaterials in regard to their unique stimuli responsive properties, tunable degradation rates and mechanical properties, as well as in vitro and in vivo biocompatibility.Lastly, the utility of polyphosphazenes is further extended as they are being employed in blend materials for new applications and as another method of tailoring material properties.

View Article: PubMed Central - PubMed

Affiliation: Graduate Program of Biomedical Engineering, Faculty of Engineering, The University of Western Ontario, London, ON, Canada N6A 5B9.

ABSTRACT
Degradable biomaterials continue to play a major role in tissue engineering and regenerative medicine as well as for delivering therapeutic agents. Although the chemistry of polyphosphazenes has been studied extensively, a systematic review of their applications for a wide range of biomedical applications is lacking. Polyphosphazenes are synthesized through a relatively well-known two-step reaction scheme which involves the substitution of the initial linear precursor with a wide range of nucleophiles. The ease of substitution has led to the development of a broad class of materials that have been studied for numerous biomedical applications including as scaffold materials for tissue engineering and regenerative medicine. The objective of this review is to discuss the suitability of poly(amino acid ester)phosphazene biomaterials in regard to their unique stimuli responsive properties, tunable degradation rates and mechanical properties, as well as in vitro and in vivo biocompatibility. The application of these materials in areas such as tissue engineering and drug delivery is discussed systematically. Lastly, the utility of polyphosphazenes is further extended as they are being employed in blend materials for new applications and as another method of tailoring material properties.

Show MeSH
Related in: MedlinePlus