Cellulose is one of the most commonly found biopolymers on the earth, it can be found in plants, some species of bacteria, algae, fungi, and shellfish. Such properties as hydrophilicity, mechanical strength, possibilities of chemical modification and biocompatibility make cellulose an interesting polymer for biomedical applications.

Nanostructured cellulose merits special attention. This material consists of cellulose fibrils or crystallites measuring at least one dimension on the nanoscale. It has the properties of cellulose combined with nanostructured materials' special properties, such as a high specific surface area and distinctive structural features. Although, depending on the processing method used to produce the nanomaterial, nanocellulose properties such as fibre size and surface charge can vary greatly.

In the last decade, nanocellulose research has made tremendous progress, but its application to biomedicine still requires further exploration, especially in the interplay with biological systems. It is therefore necessary to facilitate the development of nanocellulose materials for biological purposes and applications.

Differences between cellulose and nanocellulose.


Plant fibres are natural sources of cellulose. In nature, these biocomposites occur in complex combinations. The elementary plant fibre is a single cell, usually between 1 and 50 µm long and about 10-50 µm in diameter. A single fibre looks like a microscopic hollow tube in which a wall of cells surrounds the central lumen. The cell wall of the fibre consists of an outer primary P-wall and an inner secondary S-wall. The thin P-wall (~ 100-200 nm thick) contains a loose network of microfibrils. The S-wall is 3-6 µm thick and consists of three layers: S1, S2, and S3. The S1 and S3 layers are nanoscales, and the S2 layer has a thickness of approximately 2-5 μm. The dominant layer S2 consists of a series of spirally wound cellulose microfibrils (CMF), which are oriented at an acute angle to the fibre axis.


CMF is a cell wall containing an amorphous matrix that consists of lignin, hemicelluloses, proteins and extractive organic substances. The CMF and hemicelluloses are bound to each other by hydrogen bonds. On the other hand, hemicelluloses are more tightly bound to each other by lignin through single-valent bonds, that is, the hemicellulose component is the stabilizer between cellulose and lignin. A CMF with a diameter of 10-30 nm consisting of 30-100 cellulose can lead to an increase in molecular length.


The structure and chemical composition of plant fibres differ from one another and depend on species, age, growth, and climate. This leads to considerable variation in fibre characteristics and leads to difficulties in establishing a quality standard. Variability in the structure and composition of plant fibres contributes to the variability in plant fibre structure and composition contributes to the mechanical properties and strength of cellulose. 


Contrarily, nanocellulose is a cellulose fibre that can be extracted. Nanocellulose fibre size, which is typically less than 100 nm in diameter and micro-nanocellulose is a biodegradable nanofiber with a low density (approximately 1.6 g/cm3) and good strength. It has a rigidity of up to 220 GPa, which is considerably high. Nanocellulose also possesses a high tensile strength (up to 10 GPa), which is greater than cast iron, and a strength-to-mass ratio eight times greater than stainless steel. Nanocellulose also has transparent and reactive surface hydroxyl groups that are functionalized with various surface characteristics.


Nanocellulose can be divided into three main types: nanocrystalline nano fibrillated, bacterial, and nanocrystalloid fibrous cellulose. Due to variations in sources and extraction processes, all forms differ in morphology, particle size, crystallinity, and certain characteristics. 

  • Nanocrystalline cellulose - known as cellulose nanocrystals or cellulose nanowhiskers, is a high-strength nanocellulose that is usually extracted from the cellulose fibril by acid hydrolysis. It has a short rod-shaped, or whisker shape, with 2-20 nm in diameter and 100-500 nm in length. In addition, it contains 100% of the chemical composition of cellulose mainly in crystalline areas (high crystallinity of about 54 88%). The crystalline components are retained while the amorphous parts are hydrolyzed and eliminated by acid.
  • Nanofibrillated cellulose - known as cellulose microfibrils, micro fibrillated cellulose, cellulose nanofibrils, cellulose nanofibrils, or nanofibrillar cellulose, is a long, flexible, and tangled nanocellulose that can be extracted from cellulose fibrils by mechanical methods. It has long fibrillar shapes from 1-100 nm to 500-2000 nm in diameter. In addition, it contains 100% cellulose in the chemical composition of the crystalline and amorphous regions. Compared to nanocrystalline cellulose, nanofibrillated cellulose has a longer length with a high length to diameter ratio, a high specific surface area, and a high level of hydroxyl groups, which easily enter into surface modification. 
  • Antimicrobial materials. Interest in using nanocellulose to treat or prevent bacterial infections is based on the fact that it can provide a porous network useful for potential antibiotic transport and can also act as a physical barrier. Since nanocellulose itself has no antimicrobial properties, it is necessary to introduce antimicrobial agents (e.g., silver nanoparticles, lysozyme). Another approach is to chemically modify the nanocellulose material to obtain the desired antimicrobial effect. Some examples of investigated nanocellulose-based materials with antimicrobial activity include: cellulose acetate-based nanofibers containing the antimicrobial agent N-gallamine, aminoalkyl grafted BC films, nanohybrid materials with NCC containing dendritic nanostructured silver, and amino-modified NFC. The study of nanocellulose biocompatibility becomes obligatory if the use of nanocellulose for medical purposes is to be studied.

Nanocellulose in biomedicine  

Most studies in the field of biomedical use of cellulose-based materials involve bacterial nanocellulose. This is due to the fact that compared to cellulose from plant sources, bacterial nanocellulose has a higher water retention capacity, high crystallinity, high strength, and higher purity. Bacterial nanocellulose has a unique nanofiber morphology, which to some extent mimics the properties of the extracellular matrix. There are several possible reasons for this phenomenon: production costs are relatively low compared to other biopolymers, cellulose is widely available, sources are stable, and the material has high mechanical properties,  a large specific surface area, presents a wide possibility of chemical modifications, is biocompatible and non-toxic.

In addition to all of this, nanocellulose is biodegradable, easily accessible, and inexpensive. The great need for biodegradable and sustainable natural resources has prompted study into nanocellulose manufacturing and usage methods. Nanocellulose has been made in a variety of forms researchers use a variety of precursors and techniques (chemical and mechanical). This nanocellulose with improved properties has a wide range of biomedical uses. As polymer nanocomposites, nanocellulose has also been employed. Researchers have high expectations for nanocellulose, which, due to its unique characteristics, hold the potential for the development of bio-nanocomposite materials. For example, nanocellulose may be used as a deformable material, which has such properties as plastic so that it can replace plastic bottles and containers, and hence, it would be a good solution to soil pollution.