Current requirements for polymeric biomaterials in otolaryngology

Biodegradable Polymers in Biomedical Applications: A Review-Developments, Perspectives and Future Challenges

Biodegradable polymers are materials that, thanks to their remarkable properties, are widely understood to be suitable for use in scientific fields such as tissue engineering and materials engineering. Due to the alarming increase in the number of diagnosed diseases and conditions, polymers are of great interest in biomedical applications especially. The use of biodegradable polymers in biomedicine is constantly expanding. The application of new techniques or the improvement of existing ones makes it possible to produce materials with desired properties, such as mechanical strength, controlled degradation time and rate and antibacterial and antimicrobial properties. In addition, these materials can take virtually unlimited shapes as a result of appropriate design. This is additionally desirable when it is necessary to develop new structures that support or restore the proper functioning of systems in the body.

An artificial silk elastin-like protein modifies the polarization of human macrophages line THP-1

A silk elastin-like protein (SELP) is an artificial compound with silk fibroin-like and elastin-like tandem repeats. The objective of this study is to evaluate the influence of SELP on the polarization of human monocytoma cell line (THP-1)-derived macrophages. When the macrophages of inflammation-type (M1) were cultured with different concentrations of SELP solution, the secretion of a pro-inflammatory cytokine, tumor necrotizing factor (TNF) -α was significantly suppressed at the higher concentrations. In addition, the secretion of an anti-inflammation cytokine, interleukin (IL)-10, was significantly enhanced from the macrophage of M0-, M1-, and M2-types. By the incubation with soluble SELP, the morphology of M2-type macrophages changed to be of an extended shape. Following incubation with the sponge of SELP, M0-type macrophages secreted IL-10 with time. It is concluded that the SELP itself in solution has an ability to induce the anti-inflammation of M2-type macrophages.

An Artificial Silk Elastin-Like Protein Modifies the Polarization of Macrophages

A silk elastin-like protein (SELP) is an artificial compound with silk fibroin-like and elastin-like tandem repeats. The objective of this study is to evaluate the influence of SELP on the polarization of mouse bone marrow-derived macrophages. When the macrophages of inflammation-type (M1) were cultured with different concentrations of SELP solution, the secretion of a pro-inflammatory cytokine, tumor necrotizing factor (TNF)-α, was significantly suppressed at the higher concentrations. In addition, the secretion of an anti-inflammation cytokine, interleukin (IL)-10, was significantly enhanced from the macrophage of an original type (M0). By the incubation with soluble SELP, the morphology of M0- and M1-type macrophages changed to be of a round shape with a large size. Following incubation with the sponge of SELP, the M0-type macrophages secreted IL-10 with time. When injected into an air pouch of mice subcutis which had been prepared by the injection of air, the SELP sponge and 5 wt % of SELP solution induced IL-10 secretion to a significantly high extent compared with the saline injection. Cells isolated from the air pouch 24 h after the injection were stained by the CD206 of a M2 marker. It is concluded that the SELP itself in solution has an ability to induce the anti-inflammation M2-type macrophages.

Biocompatible Materials in Otorhinolaryngology and Their Antibacterial Properties

For decades, biomaterials have been commonly used in medicine for the replacement of human body tissue, precise drug-delivery systems, or as parts of medical devices that are essential for some treatment methods. Due to rapid progress in the field of new materials, updates on the state of knowledge about biomaterials are frequently needed. This article describes the clinical application of different types of biomaterials in the field of otorhinolaryngology, i.e., head and neck surgery, focusing on their antimicrobial properties. The variety of their applications includes cochlear implants, middle ear prostheses, voice prostheses, materials for osteosynthesis, and nasal packing after nasal/paranasal sinuses surgery. Ceramics, such as as hydroxyapatite, zirconia, or metals and metal alloys, still have applications in the head and neck region. Tissue engineering scaffolds and drug-eluting materials, such as polymers and polymer-based composites, are becoming more common. The restoration of life tissue and the ability to prevent microbial colonization should be taken into consideration when designing the materials to be used for implant production. The authors of this paper have reviewed publications available in PubMed from the last five years about the recent progress in this topic but also establish the state of knowledge of the most common application of biomaterials over the last few decades.

Effectiveness of degradable and non-degradable implants to close large septal perforations in an experimental model

Background Reparation of large nasal septum perforations continues to be challenging. Bipedicled mucoperichondrial and inter-positional grafts currently show the most promising results. New implants have emerged to be used as a support membrane to carry on the mucosal cells, taking advantage of the innate proliferative properties of the mucosal tissue. Objective To compare the effectiveness of two kinds of material; non-absorbable dimethylsiloxane (silicone elastomers) and absorbable porcine small intestinal submucosa (Surgisis), both used as an inter-positional graft without neighbouring flaps to close nasal septal perforations in an experimental model. Methods Fifteen dogs were divided into three groups. One group received Surgisis, the other sheets of dimethylsiloxane and the last group a sham group. The dogs were followed for 6 weeks. Results The initial perforation of the nasal septum showed complete mucosal closure in the dimethylsiloxane group. The Surgisis group, on the other hand, had a smaller reduction than that at the beginning (final mean area = 23.0 ± 5.4 mm(2) (p < 0.05); however, complete closure was not achieved. Sham animals showed an inconstant and slight reduction in dimension from 100 mm(2) to 70 ± 16 mm(2) of mucosa and cartilage, but closure was not achieved. A significantly higher number of capillaries were observed in the Surgisis group compared to the dimethylsiloxane group (p < 0.05) without differences in inflammation, fibrosis, or necrosis. Conclusions The non-absorbable implant; dimethylsiloxane facilitates a better closure of the nasal septum.

[The long-term results of the application of the polypropylene mesh for the plastic correction of extensive laryngo-tracheostomas]

The objective of the present study was to estimate the long-term results of the closure of large laryngeal and tracheal stomas with the use of the polypropylene mesh. The study included 33 adult patients presenting with extensive laryngeal and tracheal stomas. A total of 34 surgical interventions were performed for alloplastic correction of these defects. The complete closure of the tracheal and laryngeal defects with the incorporation of the prosthesis and restoration of respiration was achieved in 88.2% of the alloplastic procedures. The long-term follow-up of the treated patients (median: 75 months) failed to reveal any signs of mesh rejection. Moreover, none of the patients reported an appreciable feeling of discomfort at the site of mesh localization. Thus, the results of the study indicate that the alloplastic correction of laryngeal and tracheal stomas with the implantation of the modern mesh prostheses from polypropylene monofilaments provides the safe and reliable alternative to autoplastic surgery. Low rigidity of the modern prosthetic meshes ensures good immediate results of implant survival in the absence of long-term complications associated with the durable presence of the polypropylene mesh on the neck.