Nanofibres

Author

Asst. Prof. Ece Guler

Faculty Member - Istanbul Kent University Faculty of Pharmacy, Department of Pharmacology, Kağıthane 34406 Istanbul, Turkey Researcher - Nanotechnology and Biomaterials Application and Research Centre, Marmara University, Istanbul 34722, Turkey

"Nanofibres are a promising nanopharmaceutical product for the future."

What is nanotechnology?

The concept of nanotechnology, which was first used by Norio Taniguchi in 1974, covers all engineering and technology studies carried out in the nano dimension. Today, developments in nanotechnology are utilised in many different fields such as biology, pharmacy, physics, chemistry, medicine and space. Especially in the field of health, the benefits of nanotechnology are utilised in increasing the effectiveness of existing drugs with nanoscale drug carrier systems, in cases where molecular scale intervention in the body is required, and in providing diagnosis and treatment more effectively.

What is nanofiber?

Drug carrier systems that can vary between 1 and 1000 nm in diameter, produced using polymers, resembling hair strands are called nanofibres.

What are nanofiber production techniques?

Bicomponent extrusion, template synthesis, self-assembly, phase separation, melt blowing, electrospinning and pressurized gyration are the most preferred nanofibre production techniques.

What are the advantages of nanofibers?

Nanofibers have features such as large surface area/volume ratio, flexibility, small diameter and controllable pore size, high tortuosity, high permeability, biocompatibility, biodegradability, easy functionalization, enabling material combination, hydrophilic or hydrophobic properties, relatively low cost, and mass production capacity.

What are the uses of nanofibers?

Thanks to their advantages, nanofibres are used as a biomaterial in electrochemical production, sensor production, drug carrier system development, air and water filter production, food packaging, energy, textile industry, and tissue engineering.

The role of nanofibers in tissue engineering

Tissue engineering is a field of engineering that deals with the reconstruction or replacement of non-functional tissues and organs using bioactive components and stem cells. A controlled degradation rate is very important for tissue engineering studies. The scaffold developed for therapeutic purposes should degrade within the time period during which newly regenerated tissues develop. Fibers are a drug carrier system that attracts a lot of attention and studies on imitation of tissue or organ due to their similarity to the extracellular matrix, circulation of oxygen and nutrients as well as the removal of metabolic wastes, chemistry suitable for the surfaces of tissues, interconnected porous network structures, high porosity and surface area/volume ratio suitable for proliferation of cells, high drug loading capacity, and appropriate mechanical strength. In addition, nanofibers whose surface is functionalized with growth factors, drugs, peptides, cytokines, and other bioactive molecules promise better treatment results in tissue engineering studies. Thus, they play a very effective role in providing targeting, accelerating tissue regeneration, controlling the level of inflammation, and improving vascularisation. With all these advantages, nanofibers continue to be studied in various tissue types such as skin, bone, cartilage, heart, nerve, vessel, tendon, and ligament in tissue engineering applications.

Nanofibers as a drug delivery system

Nanofibers as drug delivery systems can be used to encapsulate a wide range of therapeutic agents including antibiotics, antioxidants, antitumour, anti-inflammatory, antidiabetic, anti-Alzheimer's drugs as well as biomacromolecules such as proteins, antibacterial peptides and DNAs, and plant extracts. This versatility allows nanofibers to be used for a wide variety of therapeutic purposes. The applications of nanofibers in drug delivery systems are rapidly expanding with their high drug loading capacities, controlled drug release profiles and increased bioavailability and reduced side effects of drugs. The speed and rate of release of the drugs encapsulated in the fibers varies depending on the degradation rate, swelling behaviour, porosity and diameter of the fibers. For this reason, the speed and rate of drug release can be adjusted by changing the physical parameters of the polymer solution to be used in fiber production and the parameters of the selected fiber production technique.

The role of nanofibres in wound treatment

One of the most popular uses of fibers is wound healing. Wounds can be divided into acute and chronic according to their healing time. While surgical wounds or knife cuts are examples of acute wounds that heal quickly, a diabetic foot ulcer is a chronic wound and is difficult to heal. Since chronic wounds tend to become infected and inflamed, difficulties in the wound healing process are an important problem for the medical field. The dressing applied to the wound acts as a protective barrier against infection and accelerates wound healing. Although bandages and gauze dressings are effective in minimising the risk of infection and protecting against pathogens to some extent, depending on the condition of the wound, they are not very effective in providing comprehensive infection protection, optimising the wound healing environment and supporting the wound repair process. However, the use of nanofibers in wound healing provides effective isolation of the wound against external factors, protection against bacterial infections, absorption of exudates from the wound surface, gas permeability, providing a suitable moist environment, demonstrating anti-inflammatory effect, creating suitable conditions that accelerate cell proliferation for the regeneration of injured tissue and accelerating the healing process. In addition, increased tissue regeneration with the use of nanofibers in stem cell therapy used in the treatment of severe wounds is promising. However, in order to encourage cells to adhere to the surface of nanofibers, proliferate on the surface of nanofibers, and infiltrate into the reticular structures of nanofibers, hydrophilic natural polymers and especially substances such as collagen, hyaluronic acid and fibronectin found in skin tissue to increase wound repair are preferred together with synthetic polymers used in nanofiber production.

Nanofibers in the treatment of central nervous system diseases

The most difficult point in the treatment of central nervous system diseases (such as Alzheimer's disease, epilepsy, and Parkinson's disease) is the blood-brain barrier (BBB). The BBB is a selectively permeable barrier that allows the passage of lipophilic molecules with low molecular weight (<500 Da) while preventing inflammation, disease agents, xenobiotics, therapeutics, and pathogens into the brain. For this reason, the desired success in treatments cannot be achieved due to the high molecular weights and low targeting capabilities of today's preferred treatment strategies. With the developments in nanotechnology, the problems in overcoming the BBB have been overcome by the development of nano-sized drug carrier systems. Nanofibers are effective in the treatment of central nervous system diseases with their nano diameters. However, drug-loaded nanoparticles can also be embedded in the fibers. Nano-sized drug carrier systems can be targeted to the BBB, neurons, or other specific regions in the brain with direct or indirect targeting techniques. Thus, drugs can be loaded into nano-sized drug carrier systems, increasing the bioavailability of drugs and enabling them to reach the targeted area and providing high efficacy in treatment with low dose and dosing numbers. Transdermal, sublingual, oral drug administration routes provide a highly effective, easy, increased patient compliance, and a relatively inexpensive treatment strategy.

Use of nanofibers in filtration

There are a wide variety of bioaerosols such as viruses, bacteria, fungi, and pollen in the atmospheric air and these bioaerosols can cause many health problems such as allergies, infectious diseases, and respiratory system diseases such as COPD, asthma, and cancer. Their low settling velocities and small diameters cause these particles to remain in the atmosphere longer than other aerosols. Currently, the use of nanofibers in filtration is considered to be the most effective physical approach against air pollutants. Nanofiber membranes can capture most air pollutants and show high efficiency.

The role of nanofibers in face mask

The high drug loading capacity of nanofibers, their biodegradability, their ability to be produced in more than one layer, their ability to encapsulate different drugs in different layers, and the ability to adjust drug release profiles depending on the chemical structures of the polymers used during their production have made nanofibers preferred in the cosmetics industry. Nanofibers loaded with drugs such as vitamin A, hyaluronic acid, collagen, vitamin C, and resveratrol have started to be produced as detention and face masks to protect the skin against aging, moisturize, tighten, revitalize, remove dry lines, and wrinkles. Thus, it is expected to provide more effective skin care with increasing bioavailability of drugs.

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