Design, synthesis, and pr eliminary characterization of tyrosine-containing polyarylates: New biomaterials for medical applications

Fiordeliso, James J.; Bron, S.; Kohn, Joachim

doi:10.1163/156856294x00176

Cited by 45 publications

(33 citation statements)

References 17 publications

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“…4,18 Poly(DTE carbonate) was purified by precipitation of a polymertetrahydrofuran solution into ethyl ether. Medical grade PLLA (IV = 0.88 dL/g in methylene chloride) was obtained from Birmingham Polymers (Birmingham, AL) in pellet form.…”

Section: Methodsmentioning

confidence: 99%

“…4 Through small changes in the chemical structure of the respective monomers, different polycarbonates and polyarylates have been prepared that exhibit a wide range of material, chemical, and physical properties. 2,5,6 Among the polycarbonates, previous studies have demonstrated that poly(DTE carbonate) has particularly favorable interactions with hard tissue and is a promising polymer for use in orthopedic applications. 7 Among the polyarylates, poly(DTE adipate) has been investigated in several studies.…”

Section: Introductionmentioning

confidence: 99%

“…7 Among the polyarylates, poly(DTE adipate) has been investigated in several studies. 4,6,8 Both of these polymers were shown to degrade in vitro, albeit at different rates. In addition, they exhibited minimal cytotoxicity in vitro and supported the attachment and growth of various cell types.…”

Section: Introductionmentioning

confidence: 99%

“…In addition, they exhibited minimal cytotoxicity in vitro and supported the attachment and growth of various cell types. 2,4,9 In this study, the in vivo degradation, tissue response, and long-term biocompatibility of tyrosine-derived polycarbonates and polyarylates were further investigated. For this purpose, poly(DTE carbonate) and poly(DTE adipate) were selected as model compounds, and PLLA was included as a control.…”

Section: Introductionmentioning

confidence: 99%

“…Time points usually are selected in an arbitrary manner such that each is a factor of the previous one, with an increasing amount of time between each point (i.e., 3,6,12, and 24 months). 5,7,10 While this approach works well for the evaluation of nondegradable materials, with degradable materials having different degradation rates, the use of a preselected time scale can be problematic.…”

Section: Introductionmentioning

confidence: 99%

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Comparative histological evaluation of new tyrosine-derived polymers and poly (L-lactic acid) as a function of polymer degradation

Hooper

Macon

Kohn

1998

J. Biomed. Mater. Res.

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Previous studies demonstrated that poly(DTE carbonate) and poly (DTE adipate), two tyrosine-derived polymers, have suitable properties for use in biomedical applications. This study reports the evaluation of the in vivo tissue response to these polymers in comparison to poly(L-lactic acid) (PLLA). Typically, the biocompatibility of a material is determined through histological evaluations as a function of implantation time in a suitable animal model. However, due to changes that can occur in the tissue response at different stages of the degradation process, a fixed set of time points is not ideal for comparative evaluations of materials having different rates of degradation. Therefore the tissue response elicited by poly(DTE carbonate), poly(DTE adipate), and PLLA was evaluated as a function of molecular weight. This allowed the tissue response to be compared at corresponding stages of degradation. Poly(DTE adipate) consistently elicited the mildest tissue response, as judged by the width and lack of cellularity of the fibrous capsule formed around the implant. The tissue response to poly(DTE carbonate) was mild throughout the 570 day study. However, the response to PLLA fluctuated as a function of the degree of degradation, exhibiting an increase in the intensity of inflammation as the implant began to lose mass. At the completion of the study, tissue ingrowth into the degrading and disintegrating poly(DTE adipate) implant was evident while no comparative ingrowth of tissue was seen for PLLA. The similarity of the in vivo and in vitro degradation rates of each polymer confirmed the absence of enzymatic involvement in the degradation process. A comparison of molecular weight retention, water uptake, and mass loss in vivo with two commonly used in vitro systems [phosphate-buffered saline (PBS) and simulated body fluid (SBF)] demonstrated that for the two tyrosine-derived polymers the in vivo results were equally well simulated in vitro with PBS and SBF. However, for PLLA the in vivo results were better simulated in vitro using PBS.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Comparative histological evaluation of new tyrosine-derived polymers and poly (L-lactic acid) as a function of polymer degradation

Hooper

Macon

Kohn

1998

J. Biomed. Mater. Res.

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Characterization of combinatorially designed polyarylates by time-of-flight secondary ion mass spectrometry

Belu

Brocchini

Kohn

et al. 2000

Rapid Commun. Mass Spectrom.

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A series of 16 polyarylates, with well-controlled and systematically varying chemistry, has been characterized by time-of-flight secondary ion mass spectrometry (TOF-SIMS). The polymers are structurally identical except for the incremental additions of C2H4 units to the backbone and sidechain. From the spectra, peaks characteristic of all polyarylates are identified. Furthermore, evaluation of the spectra and identification of unique signals allow classification of the polyarylates according to sidechain and backbone chemistry.

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Structure-property correlations in a combinatorial library of degradable biomaterials

Brocchini

James

Tangpasuthadol

et al. 1998

J. Biomed. Mater. Res.

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171

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A combinatorial library of degradable polyarylates was prepared. These polymers are A-B-type copolymers consisting of an alternating sequence of a diphenol and a diacid. The library was prepared by copolymerizing, in all possible combinations, 14 different tyrosine-derived diphenols and eight different aliphatic diacids, resulting in 8 x 14 = 112 distinct polymers. This approach (a) increases the number of available polymeric candidate materials for medical applications, and (b) facilitates the identification of correlations between polymer structure and glass transition temperature, air-water contact angle, mechanical properties, and fibroblast proliferation. The pendent chain and backbone structures were systematically varied by (a) simple homologative variations in the number of methylene groups, (b) substitution of oxygen for methylene groups, and (c) introduction of branched and aromatic structures. The polymers contained within the library exhibited incremental variations in Tg (from 2 degrees C to 91 degrees C) and air-water contact angle (from 64 degrees to 101 degrees ). Fibroblast proliferation (in vitro, serum-containing media) ranged from approximating that measured on tissue culture polystyrene to complete absence of proliferation. Generally, decreased proliferation correlated linearly with increased surface hydrophobicity, except in those polymers derived from oxygen-containing diacids in their backbone which were uniformly good growth substrates even if their surfaces were very hydrophobic. In a selected subgroup of polymers, tensile strength of thin solvent cast films ranged from about 6 to 45 MPa, while Young's modulus (stiffness) ranged from about 0.3 to 1.7 GPa. Combinatorial biomaterial libraries such as these tyrosine-derived polyarylates permit the systematic study of material-dependent biological responses and provide the medical device designer with the option to choose a suitable material from a library of related polymers that encompasses a broad range of properties.

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Design, synthesis, and pr eliminary characterization of tyrosine-containing polyarylates: New biomaterials for medical applications

Cited by 45 publications

References 17 publications

Comparative histological evaluation of new tyrosine-derived polymers and poly (L-lactic acid) as a function of polymer degradation

Comparative histological evaluation of new tyrosine-derived polymers and poly (L-lactic acid) as a function of polymer degradation

Characterization of combinatorially designed polyarylates by time-of-flight secondary ion mass spectrometry

Structure-property correlations in a combinatorial library of degradable biomaterials

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