The Influence of Tetracycline Loading on the Surface Morphology and Biocompatibility of Films Made from P(3HB) Microspheres

Abstract

Tetracycline, an antibiotic used against a broad range of Gram positive and Gram negative bacteria was encapsulated in microspheres made of poly(3‐hydroxybutyric acid) P(3HB), a microbial biodegradable polymer isolated from Bacillus cereus SPV. The drug loaded microspheres were prepared using an oil emulsion technique and compressed uniaxially to produce films. Although the same fabrication conditions were used for preparing the drug loaded and unloaded microspheres, the presence of the drug changed the surface morphology and roughness of the films. The surface morphology of the drug loaded films appeared uneven and coarser and the roughness, with an average root mean square value of 5.89 µm, was significantly higher than that of the unloaded film. The in vitro biocompatibility of the films was investigated using a human keratinocyte cell line (HaCaT) by comparing cell viability on the films to that on conventional tissue culture plastics. Both films appear to support cell growth but cell attachment and percentage cell viability were greater on the drug loaded films (32% of control) compared to the unloaded film (10% of control), possibly as a result of the non‐uniform surface morphology and increased roughness of the drug loaded film. Thus, the above results illustrate that the drug loaded films, in addition to being a suitable matrix for drug delivery, represent an improved substrate for keratinocyte cell attachment.

Microbial Polyhydroxyalkanoates and Nonnatural Polyesters

“…[375] Microspheres of poly(3HB) have been tested for releasing the antibiotics rifampicin, [380] gentamicin, [381,382] and tetracycline. [383][384][385] In another study, poly(3HB-co-3HV) microspheres and microcapsules containing tetracycline were shown to be effective against many of the periodontal disease-related bacteria. Furthermore, poly(3HB-co-3HV) and poly(3HB-co-4HB) were used as antibiotic-loaded implantable rods for the local delivery of antibiotics (Sulperazone and Duocid, Sulbactam-cefoperazone) in chronic osteomyelitis therapy.…”

Polyhydroxyalkanoates, a family of natural polymers, and their applications in drug delivery

“…PHA‐based nano/microspheres were also combined with inorganic materials in the design of composite DDS and drug‐eluting biomedical devices . Although mesoporous inorganic microparticles have been extensively studied as drug vehicles, such materials need to be chemically functionalised in order to achieve controlled drug release .…”

“…Interestingly, gentamicin was released quicker compared with tetracycline, which was attributed to the interaction between tetracycline and HA. Drug‐eluting films for potential application in the treatment of skin infections were prepared by compression moulding of tetracycline‐loaded P(3HB) microspheres . The study did not include the characterisation of drug release.…”

“…Drug-eluting films for potential application in the treatment of skin infections were prepared by compression moulding of tetracycline-loaded P(3HB) microspheres. 90 The study did not include the characterisation of drug release. However, drug-loaded films significantly improved attachment/growth of human keraritocyte cells due to the changes in surface morphology of the film and the ability of tetracycline to promote fibroblast attachment.…”

Physicochemical and Biological Characterisation of Diclofenac Oligomeric Poly(3-hydroxyoctanoate) Hybrids as β-TCP Ceramics Modifiers for Bone Tissue Regeneration

“…Moreover, the attention of many researchers was focused on the chemical modification of PHAs and their copolymers in order to reach a stable chemical bond between the active substance and the matrix of the polymer or oligomer. These approaches have led to the development of controlled release systems for active substances [ 25 , 28 , 35 , 36 , 37 , 38 ]. To the best of our knowledge, there are no reports in the literature on the synthesis of composites based on tricalcium phosphates and polyhydroxyalkanoates with covalently attached molecules of (NSAIDs).…”