Sintered electrospun poly(ɛ‐caprolactone)–poly(ethylene terephthalate) for drug delivery

Abstract

This cover by John Lannutti and colleagues demonstrates electrospun 75:25 PCL:PET following 5s acetone exposure. The biomimetic "shish-kebab" morphology is absent from pure PCL fibers following a similar acetone exposure, suggesting that the pattern of dissolution is strongly influenced by the presence of molecularly dispersed PET along the length of the fiber. Sintering of a tubular deposition of this composition at 100°C successfully produced a densified capsule that allowed for zero-order drug release over a period of 8 days. The low temperature nature of the electrospinning process avoided copolymerization; DSC suggested a post-sintering structure consisting of nanoscale PET dispersed in PCL following the original fiber direction.

Design of Biopolymer-Based Interstitial Therapies for the Treatment of Glioblastoma

“…PSA is defined as the summed surface area of all polar atoms of a drug’s chemical structure (typically oxygen and nitrogen atoms and sometimes sulfur atoms) [ 148 ]. A study by Chaparro et al found that rose bengal (PSA = 89.5 Å 2 ) had a significantly slower release rate compared to rhodamine B (PSA = 52.8 Å 2 ) from polycaprolactone (PCL) capsules [ 149 ]. It was hypothesized that the higher PSA of rose bengal compared to rhodamine B led to increased affinity with the ester groups of PCL, thus slowing the release rate of rose bengal [ 149 ].…”

“…A study by Chaparro et al found that rose bengal (PSA = 89.5 Å 2 ) had a significantly slower release rate compared to rhodamine B (PSA = 52.8 Å 2 ) from polycaprolactone (PCL) capsules [ 149 ]. It was hypothesized that the higher PSA of rose bengal compared to rhodamine B led to increased affinity with the ester groups of PCL, thus slowing the release rate of rose bengal [ 149 ]. While it is expected that rhodamine B, having the lower MW, to have a higher release rate, Chaporro et al speculate that the higher PSA also contributed towards the substantial decrease in rose bengal’s release rate [ 149 ].…”

“…It was hypothesized that the higher PSA of rose bengal compared to rhodamine B led to increased affinity with the ester groups of PCL, thus slowing the release rate of rose bengal [ 149 ]. While it is expected that rhodamine B, having the lower MW, to have a higher release rate, Chaporro et al speculate that the higher PSA also contributed towards the substantial decrease in rose bengal’s release rate [ 149 ]. This is in agreement with the findings from Liu et al, where in modeling the release of six different drugs from hydroxyl pressure sensitive adhesives, a decrease in PSA correlated with an increase in drug release at lower drug loadings of around 0.25 wt% [ 147 ].…”

“…The number of hydrogen bond donors and acceptors can also affect the degree of hydrogen bonding that can occur between the polymer and drug. For example, a drug with more hydrogen bond donors can bond more readily to a polymer backbone that can readily accept hydrogen bonds, therefore reducing the release rate [ 149 ]. Therefore, a small molecule with a high PSA may release more slowly from a polymer implant than a similar molecule with a low PSA.…”

Thermo‐oxidative degradation during sintering of polyethylene particles

“…Inspired by powder metallurgy, sintering is a well‐established procedure for producing functional polymeric parts such as separation membranes, 1 orthopedic implants, 2,3 bio‐engineered scaffolds, 4 and drug‐release media 5,6 . Also, in cases where conventional melt processing is not feasible, sintering is a viable procedure for producing polymeric parts.…”