3D-Biomaterials: Biofabrication built by Bacteria

 

Abstract

Biofabrication relates to the development of tissues and organs in medicine to meet health challenges. In almost every climate, an immense number of bacteria live, from deep oceans to below the surface of the earth or in our gastrointestinal tract. Bacteria, yeast, algae and fungal root structures, are materials grown from live microorganisms. These micro-organisms can be engineered through a bioengineering process to generate biopolymers that can be extruded to generate yarn using a spinneret or produced in a mould to generate a fibre that can be processed with zero waste. The involvement of bacteria in this process has not been established at a comparable rate, although biofabrication is rising and maturing very quickly. Researchers have used cutting-edge biofabrication techniques from the development of a new generation of biomaterials to green bioremediation to eliminate dangerous environmental pollutants or to create advanced food products in a recent trend to expose the great potential of 3D structured bacterial constructs. This is an approach towards biomaterials can fundamentally change these 3D bacterial workhouses.

Keywords: bacteria biofabrication; 3D printing; tissue engineering; probiotic food

Introduction

There is a giant symbiotic organism made up of Homo sapiens and microbial cells, whereas the genome size of the microbes in our body is greater than that of us. It gives the learning more and more about the value and contact of bacteria in our body with organs such as the liver and brain. The main role of bacteria in the development of schizophrenia has been identified in an amazing recent study. In recent years, biofabrication has advanced towards the idea of the automated production of biologically functioning standardised materials. Among other things, living cells, bioactive molecules and hybrid cell-material structures have evolved through biofabrication. Bacteria have historically not been considered to a large degree in biofabrication, however, and their tremendous potential for the production of functional 3D biomaterials has remained largely unknown. Printed bacterial patterns on the agar surface in a petri dish using soft lithography in an early analysis. The agarose stamps were manufactured for this purpose by casting agarose solutions on moulds of polydimethylsiloxane (PDMS). The cells were deposited on the surface of the stamp via the application of cell suspension, which was then used to move the bacteria pattern to agar plates containing culture media. In this area use one single stamp on the agar culture to print a bacterial pattern at least 250 times. In a concurrent, reproducible and rapid method, the recorded agarose stamp technique is capable of patterning different strains of bacteria. For various scientists interested in developing a pattern of bacteria on cell culture media, the proposed stamping technique may be helpful in studying the interaction of the species with each other, molecules or the material surface.

Background

In addition to gaining insight into the role of geometry in bacterial pathogenicity, Connell et al. Suggested a new 3D printed cellular model using a laser-based lithography method in order to better understand cell-cell interactions in a complex microbial environment. Selected bacteria have been trapped and sealed inside the cavities created by the crosslinked gelatin chains using this technique.

This paper is the interaction between human pathogens of Staphylococcus aureus and Pseudomonas aeruginosa in a 3D structure indicating the survival of S. aureus from antibiotic treatment with β-lactam when enclosed in 3D shell communities composed of P. aeruginosa. Given that a bacterial community thrives in a 3D structure in the human body, the proposed technique can be useful to study the role of geometry in pathogenicity.

Objective

The introduction into the gel of desired proteins such as bovine serum albumin (BSA) will improve the 3D structure’s mechanical and chemical properties, and it is possible to print different cell types using various manufacturing gels (Figure 1B). This created the 3D structure of bacterial cultures leading to the creation of new sustainable materials, combined the capacity of bacteria to create new materials with the tunable properties of the 3D printing process. A mixture of bacteria and alginate was extruded, cross-linked and formed a gel upon contact with a calcium ion containing surface using a modified commercial 3D printer, resulting in the reproducible preparation of 3D microbial structures. Using this technique, a high printing resolution was achieved, and the rate of extrusion and print head velocity were recorded as two major parameters affecting the printing resolution. The system that was developed allowed multilayer bacterial structures to be printed. In a bilayer structure, two different strains of Escherichia coliable for expressing proteins in separate colors were printed (Figure 2A). In addition to bacterial survival and metabolic activity, the study showed a strong separation of up to 48 hours of incubation in the gel layers. The proposed printing method can be used within a millimeter resolution for the preparation of various bacteria containing materials in a patterned format. Nevertheless, the system ‘s drawbacks involve the creation of internal bridges or hollow spaces for 3D printed structures. Moreover, in a complex 3D structure, it is not yet possible to process bacteria directly. Also, biofilm production is not regulated, and the chemistry of the matrix polymer can be the limiting factor in terms of the stability of the bacterial structure formed.

Methodology

By combining genetic engineering and 3D printing, a standardized and reproducible process for the development of 3D biofilm structures was produced by the same group in a recent study. To print bacterial suspension in an alginate solution that transforms into a gel on a calcium-containing substrate, a low-cost 3D printer, The Biolinker, was used. The writers have printed Engineered E. The genetic regulation of a gene (csgA) could regulation coli that produces biofilm in the presence of an inducer and the formation of biofilm. These biofilms printed in 3D could have different functions and applications, such as metal ion sequestration or filtration by water. The dough formulation, the type of flour and the content of water decide the viability of printing the dough in 3D structures, much like hydrogel composition, which affects viscosity and printability.

Probiotic-loaded bacterial structures were printed in two honeycomb and concentric structures using a fused deposition modelling system (Figure 3) and baked at different temperatures of 145, 175 and 205 ° C. The survival of the organism at the baking temperature is one significant obstacle to manufacturing bakery products containing probiotic bacteria. In this respect, it can help shorten the baking time by increasing the drying rate of the products. Therefore, food structures created by the 3D printing method with high surface-to – volume ratios can be advantageous for this reason. In order to increase the viscoelastic properties of the dough to improve its printability, the authors have added sodium caseinate. The probiotics could survive the 6-minute baking process in honeycomb structures at 145 ° C, and the baked product could be characterized as a probiotic food and its spatial distribution in the 3D structure by having more than 106 CFU / g. With two examples of 3D structures for bioremediation and biomedical applications, the authors demonstrated the capability of the built framework. In the first case, this bacterium was immobilized and 3D-printed in order to benefit from the phenol-degrading capability of Pseudomonas putida. The high surface area of the 3D bacterial lattice structure could degrade the phenol as a major and toxic substance without the need for a support material. Bacteria that were released from the 3D structure in the phenol-containing medium as well as the cells immobilized on the surface of the 3D structure were found to be causing the degradation of phenol. In the second case, for the in-situ development of cellulose in the form of a 3D structure with good mechanical properties, Flink was loaded with the Type equation here. acetobacter xylinum, making it suitable for biomedical applications. In this case, the inkre sidue was washed away once cellulose was formed by the bacteria, leaving a cellulose network with a specific geometry and topography.

The shear-thinning rheological activity of the cell-containing ink was ideal for 3D extrusion printing. The structures of printed cells will ferment glucose and generate ethanol and CO2. For a wide range of biotechnological applications, the proposed ink system in this study can be used for printing various microbes with catalytic activities. The 3D fabrication of bacteria may also help the food industry.

Y-the dough composition, the type of flour and the content of water determine the feasibility of 3D dough printing structures. Bacterial structures were printed in two honeycombs and concentric structures using a fused deposition modelling system (Figure 3) and baked at 145, 175 and 205 ° C at different temperatures. One big obstacle to the production of bakery products containing probiotic bacteria is the survival of the organism. The baking temperature. In this respect, it will help to shorten the baking time by increasing the drying rate of the products. Therefore, the printing method can be advantageous for food structures with high surface-to – volume ratios produced by 3D for this purpose. To increase the viscoelastic properties of the dough to enhance its printability, sodium caseinate was incorporated by the authors.

Result

Microbial biofilm models are the major form of microbial life, which are composed of a microorganism and extra polysaccharides. These 3D structures can be used to evaluate microbial metabolism and their interaction with the surrounding media. This research is focused on engineering 3D printed biofilms of methanotroph bacteria with specific characteristics in order to convert methane into various organic materials, such as bioplastics. This can result in the reduction of the methane emitted into the environment and at the same time result in the development of bio-based materials as an intersection of technology and nature. In another study, a microporous 3D bacterial cellulose foam was developed through foaming, and bacterial cellulose was formed directly at the air–water interfaces of the air bubble (Figure 4A). The authors used Cremodan as a surfactant for foaming and Xanthan as a thickener to obtain the stable foam. Biocompatible 3D structured bacterial cellulose may have potential applications in the engineering of skin tissue and wound healing, addressing the lack of porosity of conventionally generated bacterial cellulose. In a recent innovative research, on biotic and abiotic (polysiloxane) mushroom pileus, Manoor ‘s lab 3D printed colonies of cyanobacteria and graphene nanoribbons and created bionic mushrooms (Figure 4B). In order to produce photosynthetic electricity collected using graphene nanoribbons, the highly packed 3D printed bacteria may feed from the mushroom. Interestingly, the biotic mushroom provided a favorable atmosphere for bacteria (e.g. temperature, pH and humidity) that helped to ensure their viability.

Conclusion

In conclusion, the state-of-the-art biofabrication of bacterial constructs was outlined, highlighting the performance and unmet challenges from this point of view. The potential application of 3D printed bacterial constructs is diverse, ranging from in vivo research on the development of infections to 3D structured production of probiotic foods, conversion of methane into bioplastics, production of photosynthetic electricity, and biomedical applications. Despite these fascinating studies and documents, the present 3D bioprinters are slow and operate on small scales. Future studies are needed in order to develop new 3D bioprinters that are inexpensive, scalable and able to print different types of bacterial inks with different viscosities in a short time and in a controlled fashion. Given the strong and rising demand for green products and the potential applications of 3D printed bacterial constructs, it is highly predictable that these barriers will soon be overcome.

Future visions

When 3D printing progresses, it becomes apparent that for specific clinical applications, we will need dedicated printing systems. For the task at hand, the printer in the cartilage regeneration surgery will be explicitly constructed, with only essential variables installed into a powerful and reliable system. In the public sector, properly qualified individuals will also find roles, preferably in regulatory bodies or community participation.

We need to prepare today for this work of tomorrow and new opportunities are emerging biofab-masters-degree opportunities. We need to cut through the conventional academic barriers that are slowing down such development. We need to connect with the population of traditional producers with skills that can be built on for sectors of the next generation

References 

1. Ley, R.E.; Peterson, D.A.; Gordon, J.I. Ecological and evolutionary forces shaping microbial diversity in the human intestine. Cell2006,124, 837–848.
2. Shanahan, F. The host-microbe interface within the gut. Best Pract. Res. Clin. Gastroenterol. 2002, 16, 915–931
3. Zheng, P.; Zeng, B.; Liu, M.; Chen, J.; Pan, J.; Han, Y.; Liu, Y.; Cheng, K.; Zhou, C.; Wang, H.; et al. The gut microbiome from patients with schizophrenia modulates the glutamate-glutamine-GABA cycle and schizophrenia-relevant behaviours in mice. Sci. Adv. 2019, 5, eaau8317
4. Moroni, L.; Boland, T.; Burdick, J.A.; De Maria, C.; Derby, B.; Forgacs, G.; Groll, J.; Li, Q.; Malda, J.; Mironov, V.A.; et al. Biofabrication: A Guide to Technology and Terminology. Trends Biotechnol. 2018, 36, 384–402.
5. Weibel, D.B.; Lee, A.; Mayer, M.; Brady, S.F.; Bruzewicz, D.; Yang, J.; DiLuzio, W.R.; Clardy, J.; Whitesides, G.M. Bacterial Printing Press that Regenerates Its Ink: Contact-Printing Bacteria Using Hydrogel Stamps. Langmuir 2005, 21, 6436–6442.
6. Connell, J.L.; Ritschdorff, E.T.; Whiteley, M.; Shear, J.B. 3D printing of microscopic bacterial communities. Proc. Natl. Acad. Sci. USA 2013, 110, 18380.