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[The reconstruction of bioengineer active corneal stroma and its biocompatibility study].

This paper aims to explore the biocompatibility of bioengineer active corneal stroma (BACS), as the biological carrier for cornea reconstruction, to provide the basis for future study on clinic application. The cells and immunogenic components of cornea stroma were removed through different extract methods. A complex of functional corneal stroma cells and acellular corneal stroma was used to reconstruct BACS. Their morphological characteristics and ultrastructures were observed with transmission electron microscope. The complex was grafted into interlamellar stromal pockets. Cells were labeled by BrdU to examine the survival and conversion after grafting. The cells could survive and proliferate in acellular corneal stroma. All the nuclei of the corneal stromal cells showed positive labeling with BrdU in the BACS. After 4 weeks, BACS became transparent; after 8 weeks, the bioengineer active cornea stroma was fully reconstructed.

Animals↗

[Application and effectiveness of soil bioengineering in ecological restoration of stream bank].

Soil bioengineering is a kind of engineering by using living plant materials to construct the structures with some engineering and ecological functions, which can provide an effective means for the slope stabilization and site restoration of stream banks. In this paper, the principles of soil bioengineering, basic planting methods, live stakes, live fascines, brush layering, and integrated technologies were discussed in brief, and the first demo project of soil engineering in ecological restoration of stream bank in our country was introduced. After 10-month project implementation, significant effectiveness was obtained on slope stability, habitat improvement, and ecological restoration of stream banks. It was concluded that the approach could be widely applied in ecological restoration of all kinds of slopes in China.

Agriculture↗

Symbiosis: nursing and the bioengineer.

At this time, bioinstrumentation is the product of the possible as modified by what is practical. The bioengineer offers both the possible and the practical from an engineering and ideal model. The nurse, in contrast, speaks to the ideal possible from a confining practical clinical model. Symbiosis of nursing and bioengineering will combine the important attributes of each discipline for the betterment of patient care. In truth, the machine becomes an instrument of humanity.

Biomedical Engineering↗

Bioengineering principles of hydrotherapy.

Hydrotherapy is based on several important bioengineering principles that permit the design and development of aquatic exercise devices, techniques and programs. These principles involve several forces (buoyancy, drag, inertia), hydrostatic pressure and the specific heat of water. By acquiring a knowledge of these bioengineering principles, an individualized exercise program can be prescribed that will enhance physical fitness which is associated with desirable psychological changes.

Biomechanical Phenomena↗

A voyage of reprogrammable metabolic bioengineering reshapes plant defense: from editing tools to synthetic systems.

Metabolic bioengineering has emerged as a transformative approach for reshaping plant defense by targeting intrinsic biosynthetic pathways to enhance immunity in modern agriculture. Moving beyond proof-of-concept metabolomics to broad-spectrum programmable pathway engineering addresses gaps in plant rational design and optimizes resilience in response to diverse environmental cues. This review aims to comprehensively highlight the transition of innovative approaches to phenolics, alkaloids, flavonoids, terpenoids, and benzoxazinoids, inferring adaptive reprogramming that mediates the growth-defense balance and functions as molecular sentinels in plants. Furthermore, decoding the volatile metabolome reveals a dynamic signaling interface that influences defense responses and stress-induced plant-microbe interactions, with the shikimate, jasmonate, and salicylate pathways functioning as central hubs for microbial deterrence and priming immune memory. Recent developments in multi-scalar genome-editing strategies, including CRISPR-driven combinatorial edits, enzyme orthogonalization, fluxomics, and spatially resolved multi-omics, reconfigure central and specialized metabolic fluxes toward improved defense function and regulation. Additionally, emerging tools, such as WUSCHEL2 and BABY BOOM transcriptional modules, and artificial engineering strategies integrating deep learning model-driven predictions facilitate rapid development of synthetic genetic circuits and support a predictive engineering of plants. Moreover, Mass spectrometry imaging (MSI) in spatial metabolomics enables to obtain structures and locations of unidentified endogenous metabolites within cells and tissues. Overall, this review emphasizes a diverse array of primary and secondary metabolites, spanning molecular concepts to recent advances in plant immune mechanisms. It also illustrates new frontiers in programmable metabolic engineering that accelerate the understanding of plant-microbe-metabolite cross-talks, offering strategies to improve plant resistance and advance sustainable agricultural solutions.

metabolic bioengineering↗

Contractile three-dimensional bioengineered heart muscle for myocardial regeneration.

Tissue engineered heart muscle may be able to provide a treatment modality for early stage congestive heart failure. In this study, we describe a new method to engineer functional 3-dimensional heart muscle utilizing a biodegradable fibrin gel. Primary cardiac myocytes were isolated from hearts of 2- to 3-day-old rats and processed in one of the two ways. For the first method (layering approach), the cells were plated directly on the surface of a fibrin gel-coated on polydimethylsiloxane (PDMS) surfaces. The cells were cultured in growth media and the contractile performance evaluated after formation of 3-dimensional tissue constructs. For the second method (embedding approach), the cells were suspended with thrombin and plated on 35 mm tissue culture surfaces coated with PDMS. Fibrinogen was then added to the surface. Within 7 days after initial cell plating, a 3-dimensional tissue construct of cells derived from primary heart tissue (termed bioengineered heart muscle, BEHM) resulted for both approaches. Histological evaluation showed the presence of uniformly distributed cardiac cells throughout the BEHM, both in longitudinal and cross sections. The stimulated active force of BEHMs formed using the layering approach was 835.5 +/- 57.2 muN (N = 6) and 145.3 +/- 44.9 muN (N = 6) using the embedding approach. The stimulated active force was dependent on the initial plating density. It was possible to maintain the contractile function of BEHM in culture for up to 2 months with daily medium changes. The BEHMs exhibited inotropy in response to external calcium and isoproterenol and could be electrically paced at frequencies of 1-7 Hz. We describe a novel method to engineer contractile 3-dimensional cardiac tissue construct with a fourfold increase specific force compared to our previous model.

Animals↗

Bioengineering Functional Copolymers. IX. Poly[(maleic anhydride-co-hexene-1)-g-poly(ethylene oxide)].

Amphiphilic bioengineering copolymers having a combination of hydrophilic/hydrophobic linkages and polyelectrolyte behavior, along with an ability to interact with biomacromolecules, in particular with the invertase enzyme, have been synthesized by (a) complex-radical copolymerization of maleic anhydride (MA, the acceptor) and hexene-1 (H-1, the donor) monomers with benzoyl peroxide as the initiator in 1,4-dioxane at 65 degrees C under high-conversion conditions and (b) subsequent grafting (polyesterification) of synthesized poly(MA-alt-H-1) with alpha-methoxy-omega-hydroxy-poly(ethylene oxide) (PEO). Copolymerizations were also carried out in the steady state, in order to essentially reduce the effect of copolymer composition drift. The values of the monomer reactivity ratios (r(1) and r(2)) determined by using the known terminal models of Fineman-Ross (FR) and Kelen-Tüdös (KT), as well as by nonlinear regression (NLR) analysis, are: r(1) = 0.16 and r(2) = 0.30 (FR), r(1) = 0.14 and r(2) = 0.27 (KT), and r(1) = 0.15 and r(2) = 0.29 (NLR), respectively. All the copolymers and graft copolymers were characterized by FTIR spectroscopy, (1)H{(13)C} NMR spectroscopy, viscometric measurements, and chemical (acid number), thermal (DSC and TGA), and X-ray diffraction analyses. Unlike poly(MA-alt-H-1)s, PEO macrobranched graft copolymers exhibit expressed polyelectrolyte and swelling behavior in diluted and concentrated dioxane solutions, respectively. The copolymer and its PEO hyperbranched derivatives can be used as carriers for enzyme immobilization.

Enzymes, Immobilized↗

Novel chemicals from plants via bioengineering. An overview.

Novel chemicals were traditionally extracted from medicinal plants or produced synthetically. However, new development in the field of bioengineering has allowed production of novel products from plants such as edible and industrial oils as well as specific chemicals which could be used as foods with remedial effects.

Bioreactors↗

Bioengineering aspects of heart valve replacement.

Biomedical engineering inputs have been important in the design, development and testing of substitute heart valves as well as in the pre- and post-operative management of patients with cardiac valve disease. This paper is a review of heart valve replacement whose goal is the enhancement of future bioengineering contributions. We review the approach to the patient with valvular heart disease, and the sources of early and late postoperative pathology with emphasis on complications of the prostheses used. Major significant problem areas relate to the noninvasive evaluation of cardiovascular function (both before and after surgery), device design, hemodynamics, and the need for thromboresistant and durable materials.

Biomedical Engineering↗

1992 ALZA Distinguished Lecture: bioengineering and vascular biology.

The vascular system is naturally dynamic; fluid mechanics and mass transfer are closely integrated with blood and vascular cell function. We are beginning to understand how local wall shear stress and strain modulate endothelial cell metabolism at the gene level. This knowledge may help explain the focal nature of many vascular pathologies, including atherosclerosis. Understanding mechanical control of gene regulation at the level of specific promoter elements and transcription factors involved will lead to development of novel constructs for localized delivery of specific gene products in regions of high or low shear stress or strain in the vascular system. In addition, recent research has shown how local fluid mechanics can alter receptor specificity in cell-to-cell and cell-to-matrix protein adhesion and aggregation. Knowledge of the specific molecular sequences involved in cell-to-cell recognition will allow development of targeted therapeutics, with applications in thrombosis, inflammation, cancer metastasis, and sickle-cell anemia. Bioengineers are uniquely qualified to be leaders in this field, because advances require a synthesis of cell and molecular biology with systems analysis, transport phenomena, and quantitative modeling. Rapid progress in tissue engineering applications will require this new kind of biomedical engineer, which represents both a challenge and an opportunity for our profession.

Biomedical Engineering↗

Bioengineering problems connected with the use of conventional and unconventional raw materials in fermentation. A review.

Some bioengineering problems connected with the use of conventional and unconventional raw materials in fermentation research and industry are reviewed. They include the effect of the physical state of different substrates (solid, liquid, gaseous) and considerations of physico-chemical processes, especially the identification of limiting steps. A new concept of classification of fermentors with respect to the macromixing properties is suggested and its applicability for different substrates is considered.

Bacteria↗

In Haughton's footsteps: mathematical insights into bioengineering and rehabilitation.

Four attempts are outlined which the author has made to develop mathematical models for topics encountered in bioengineering and rehabilitation. The first is autoregulation in the kidney, for which a nonlinear oscillator model is derived, based on observations of flow noise made by Erol Basar. The second is a nonlinear observer based on the theory of automatic control, developed to study patterns of spastic torque in paralysed legs via the pendulum test. The third is a design study of a skeletal muscle reflex arc involving the muscle spindle dynamics and invoking a principle of optimum stability. The final topic is an attempt to lay the groundwork for a mathematical theory of the cross-bridge or sliding filament mechanism of muscular contraction.

Biomedical Engineering↗

Protection against the co-operative toxicity of nitric oxide and oxygen free radicals by overexpression of antioxidant enzymes in bioengineered insulin-producing RINm5F cells.

AIMS/HYPOTHESIS: The importance of different antioxidative enzymes for the defence of insulin-producing cells against the toxicity of nitric oxide (NO) was characterised in bioengineered RINm5F cells. METHODS: RINm5F insulin-producing cells stably overexpressing glutathione peroxidase (GPX), catalase (CAT) or Cu/Zn superoxide dismutase (SOD) were exposed to S-nitroso-N-acetyl-D,L-penicillamine (SNAP), sodium nitroprusside (SNP) and 3 morpholinosydnonimine (SIN-1), which generate both NO and reactive oxygen species, and to the polyamine/ NO, complex DETA/NO which generates NO alone. The viability of the cells was tested by the MTT assay. RESULTS: Overexpression of antioxidant enzymes provided significant protection against the toxicity of SNAP, SNP and SIN-1, with an individual specificity related to their chemical characteristics, but was without effect upon the toxicity of DETA/NO. Cells overexpressing GPX were well protected against SNP and SNAP, while CAT was most effective against SIN-1. SOD overexpression provided less protection against the toxicity of SNAP and SNP than overexpression of GPX but was more effective in protecting against SIN-1. Co-incubation of cells with NO donors and hydrogen peroxide or hypoxanthine and xanthine oxidase showed an overadditive synergism of toxicity. CONCLUSION/INTERPRETATION: The results emphasise the importance of a synergism between NO and reactive oxygen species for pancreatic beta-cell death. Such a synergism has also been observed after exposure of beta cells to cytokines. The component of the toxicity that is mediated by oxygen radicals can be suppressed effectively through overexpression of CAT, GPX or SOD or both.

Animals↗

Bioengineered emulsans from Acinetobacter calcoaceticusRAG-1 transposon mutants.

Transposon mutants of Acinetobacter calcoaceticus strain RAG-1 were studied in an effort to control fatty acid (FA) substitution patterns of emulsan, a bioemulsifier secreted by the organism. The disrupted genes, involved in the biosynthetic pathways of biotin, histidine, cysteine or purines, influenced the level and types of FAs incorporated into emulsan. The structural variants of emulsan generated by the transposon mutants were characterized for yield, FA content, molecular weight, and emulsification behavior when grown on a series of FAs of different chain lengths from C11 to C18. Yields of emulsan from the transposon mutants were found to be lower than the parent strain and depended on the type of FA used to supplement the growth medium. Mutants 13D (His-) and 52D (Cys-) grown on LB plus C16 or C14, respectively, exhibited enhanced emulsifying activity compared to A. calcoaceticus RAG-1. The presence and composition of long chain FAs on the polysaccharide backbone influenced emulsification behavior: particularly a high mole percentage of C16 (48%) and C18 (42%). The results provide important insight into the bioengineering of bioemulsifier-producing microorganisms and provide a path towards highly tailored novel amphipathic structures to utilize as biodegradable in environmental, biomedical, and personal care applications.

Acinetobacter calcoaceticus↗

Comparison of bioengineered human bone construct from four sources of osteogenic cells.

Osteoprogenitor cells have been reported to be present in periosteum, cancellous and cortical bone, and bone marrow; but no attempt to identify the best cell source for bone tissue engineering has yet been reported. In this study, we aimed to investigate the growth and differentiation pattern of cells derived from these four sources in terms of cell doubling time and expression of osteoblast-specific markers in both monolayer cells and three-dimensional cell constructs in vitro. In parallel, human plasma derived-fibrin was evaluated for use as biomaterial when forming three-dimensional bone constructs. Our findings showed osteoprogenitor cells derived from periosteum to be most proliferative followed by cortical bone, cancellous bone, and then bone marrow aspirate. Bone-forming activity was observed in constructs formed with cells derived from periosteum, whereas calcium deposition was seen throughout the constructs formed with cells derived from cancellous and cortical bones. Although no mineralization activity was seen in constructs formed with osteoprogenitor cells derived from bone marrow, well-organized lacunae as would appear in the early phase of bone reconstruction were noted. Scanning electron microscopy evaluation showed cell proliferation throughout the fibrin matrix, suggesting the possible application of human fibrin as the bioengineered tissue scaffold at non-load-bearing sites.

Bone and Bones↗

Quantitation of putative glycoprotein X in bioengineered pseudorabies vaccine virus culture medium by ELISA.

An enzyme-linked immunosorbent assay has been developed for the detection and quantitation of putative pseudorabies glycoprotein X (gX) in bulk bioengineered PRV delta gX delta tk-1 pseudorabies vaccine virus culture medium supernatants. The assay has a dynamic range of 0.2-25 ng, with a best linear region of 0.4-12.5 ng (correlation coefficient = 0.99) which permits 1 ppm discrimination for gX.

Antigens, Viral↗

Antibodies to foot-and-mouth disease virus infection associated (VIA) antigen: use of a bioengineered VIA protein as antigen in an ELISA.

An enzyme-linked immunosorbent assay (ELISA) to detect antibodies to foot-and-mouth disease (FMD) virus infection associated (VIA) antigen (viral RNA polymerase) in cattle sera, was developed using a bioengineered VIA (BioVIA) protein antigen. Compared with the classical immunodiffusion test, with viral RNA polymerase purified from infected cell cultures as antigen, this ELISA was more sensitive. However, depending on the cattle population examined, sera with antibodies to viral RNA polymerase, probably due to infection with other picornaviruses, were detected. Despite these observations, the ELISA using BioVIA provided a rapid answer as to whether or not FMD virus circulated in a given herd of cattle. The main advantage of this ELISA is its absolute safety, since in no step of the antigen production was infectious or uninfectious FMD virus involved. The test can therefore be performed under normal laboratory conditions and no isolation units are needed as they are for the immunodiffusion test.

Animals↗

A scientist's view of bioengineering.

So, to summarize: my themes in this lecture have been: 1. Bioengineering is a many-splendoured thing. 2. There are few differences in principle between scientists and engineers, and they need to work together and respect one another's special contribution. 3. The Department of Health has done much to enhance your career structure and prospects recently; now you have to help us to polish your image even further. 4. There is urgent need for collaboration amongst all parties if we are to counter some potentially deleterious effects of the recent NHS reforms on the work of clinical scientists and engineers. Finally, I wanted to thank you for admitting me, just a little way, into the magical world of biological engineering. Life has become infinitely more exciting since you did so, and I owe you all a considerable debt of gratitude.

Biomedical Engineering↗