Research goal:
The research goal of this work is to elaborate production methods of fibrous materials from nano- and micro-fibres by electrospinning technique from solutions of biodegradable polymers
(including medical purity) for the production of medical products.
Technology and polymer feedstocks:
Nowadays electrospinning is the most effective and most often used technology of the production of nano-fibres from polymer solutions. Institute of Biopolymers and Chemical Fibres for a few years has been conducting research concerning the usage of this technology to obtain various forms of materials from nano- and micro-fibres, mainly from chitosan (also alginate, starch, collagen) and from synthetic polymers of medical purity as PLA and co-PLA (Böringer’s Resomers). Apparatus that is used for electrospinning is the laboratory equipment which is the Institute’s own technical solution that enables the production or modification of materials in form of sheets sized 20cm x 20cm and 20cm x 50cm. Production of these materials requires preparation of applicable spinning solutions with polymer concentration typically in the range 2 - 10 wt%. Solvents such as water, acids, chloroform, DMSO and others are usually used for this. Due to special requirements which are the effect of medical applications, produced materials are often subjected to additional processes in order to give them their final form. They are also subjected to mechanical examination as well as to various biological and chemical examinations which define level of their purity. In the final stage these materials have to be subjected to sterilization, mostly sterilization by radiation.
Produced fibrous materials – application directions:
implants’ modification (surgical meshes, vascular prosthesis, polyurethane wound dressing sponges, substructures of modified bacterial cellulose) – one-sided covering of permanent implants’ surface with layer of biodegradable nano-fibres in order to obtain biocompatible and biostimulative character for wound healing acceleration. In case of some implantable materials the other side is left in “slipping” form, which protects the organism from fusing an implant and the treated organ.
wound dressings in form of self-supporting fibrous coatings
culture substrates for cell cultures
We are extending given directions to new 2D forms with aligned fibres, and also we are trying to produce nano-fibrous 3D objects. We would like to add collagen, alginate or starch to biodegradable polymers that we already use: chitosan, PLA and co-PLA.
Why nano-fibres?
The results of numerous world news report that living cells proliferate much better in contact with nano-fibres than in contact with the surface of much thicker textile fibres. As the porosity of nano-fibrous wound dressing materials is small, they create a barrier for pathogensenabling at the same time an air access to the surface of the wound. Such materials in form of coating covering implants of thicker and mechanically stronger structure, can also biologically enrich the surface of the implants or they can seal the implants to prevent outflow of blood components from vascular prosthesis. We have here ability to influence the structural features of nanofibers and a wide range of polymer materials and the technique of manufacture from polymer solutions enables on the introduction of nano-sized functional additives, which preferably modify the fiber material or as a result of release them to organism, creates the environment with favorable conditions to assist the healing process. Some fibrous structures can be obtained in forms similar to natural tissues occurring in living organisms (biomimetics).
Figures:
|
|
|
Nanofibrous scaffold from chitosan / PEO composite in a state of high flexibility in the wet environment. |
Zdjęcie SEM powłoki okrywającej implant z nano i mikrowłókien PLA |
Laboratory installation for electrospinning nanofibers from polymer solutions. |
Acknowledgement:
This work was carried out as a part of the research projects: PBZ-MNiSW-01/II/2007; DWM/233/MATERA/2006 and the statutory project (P22) IBWCh/2012, all supported by the Ministry of Science and Higher Education, Poland.
Literature
Tomaszewski W., Szadkowski M., Investigation of electrospinning with use of multi-jet
electrospinning head. Fibres & Textiles in Eastern Europe No. 4 2005; 4: 22-26
Tomaszewski W., Duda A., Szadkowski M., Libiszowski J., Ciechanska D., Poly(l-lactide) Nano- and Micro-fibers by Electrospinning: Influence of Poly(l-lactide) Molecular Weight. Macromol. Symp. 2008; 272: 70-74.
Tomaszewski W., Swieszkowski W., Szadkowski M., Kudra M., Ciechanska D., Simple methods influencing on properties of electrospun fibrous mats. J Appl Polym Sci, 2012, 125(6), 4261–4266 |