SEARCH · Engineering Papers

Results for “biocompatibility”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2

All sources NASA NTRS DOE OSTI

DOE OSTI2021

Protein-assisted scalable mechanochemical exfoliation of few-layer biocompatible graphene nanosheets

A facile method to produce few-layer graphene (FLG) nanosheets is developed using protein-assisted mechanical exfoliation. The predominant shear forces that are generated in a planetary ball mill facilitate the exfoliation of graphene layers from graphite flakes. The process employs a commonly known protein, bovine serum albumin (BSA), which not only acts as an effective exfoliation agent but also provides stability by preventing restacking of the graphene layers. The latter is demonstrated by the excellent long-term dispersibility of exfoliated graphene in an aqueous BSA solution, which exemplifies a common biological medium. The development of such potentially scalable and toxin-free methods is critical for producing cost-effective biocompatible graphene, enabling numerous possible biomedical and biological applications. A methodical study was performed to identify the effect of time and varying concentrations of BSA towards graphene exfoliation. The fabricated product has been characterized using Raman spectroscopy, powder X-ray diffraction, transmission electron microscopy and scanning electron microscopy. The BSA-FLG dispersion was then placed in media containing Astrocyte cells to check for cytotoxicity. It was found that lower concentrations of BSA-FLG dispersion had only minute cytotoxic effects on the Astrocyte cells.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2024

Development of 225Ac-doped biocompatible nanoparticles for targeted alpha therapy

Abstract Targeted alpha therapy (TAT) relies on chemical affinity or active targeting using radioimmunoconjugates as strategies to deliver α-emitting radionuclides to cancerous tissue. These strategies can be affected by transmetalation of the parent radionuclide by competing ions in vivo and the bond-breaking recoil energy of decay daughters. The retention of α-emitting radionuclides and the dose delivered to cancer cells are influenced by these processes. Encapsulating α-emitting radionuclides within nanoparticles can help overcome many of these challenges. Poly(lactic- co -glycolic acid) (PLGA) nanoparticles are a biodegradable and biocompatible delivery platform that has been used for drug delivery. In this study, PLGA nanoparticles are utilized for encapsulation and retention of actinium-225 ([ 225 Ac]Ac 3+ ). Encapsulation of [ 225 Ac]Ac 3+ within PLGA nanoparticles (Z ave = 155.3 nm) was achieved by adapting a double-emulsion solvent evaporation method. The encapsulation efficiency was affected by both the solvent conditions and the chelation of [ 225 Ac]Ac 3+ . Chelation of [ 225 Ac]Ac 3+ to a lipophilic 2,9-bis-lactam-1,10-phenanthroline ligand ([ 225 Ac]AcBLPhen) significantly decreased its release (< 2%) and that of its decay daughters (< 50%) from PLGA nanoparticles. PLGA nanoparticles encapsulating [ 225 Ac]AcBLPhen significantly increased the delivery of [ 225 Ac]Ac 3+ to murine (E0771) and human (MCF-7 and MDA-MB-231) breast cancer cells with a concomitant increase in cell death over free [ 225 Ac]Ac 3+ in solution. These results demonstrate that PLGA nanoparticles have potential as radionuclide delivery platforms for TAT to advance precision radiotherapy for cancer. In addition, this technology offers an alternative use for ligands with poor aqueous solubility, low stability, or low affinity, allowing them to be repurposed for TAT by encapsulation within PLGA nanoparticles. Graphical Abstract

60 APPLIED LIFE SCIENCES↗

DOE OSTI2020

Biocompatibility of a novel heat-treated and ceramic-coated magnesium alloy (Mg–1.2Zn–0.5Ca–0.5Mn) for resorbable skeletal fixation devices

Our recent exploration into the use of biodegradable metals and surface treatments resulting in sufficient strength for skeletal reconstruction applications has led to the need to test these devices’ cytotoxicity. More specifically, our group has developed a resorbable magnesium alloy, Mg–1.2Zn–0.5Ca–0.5Mn, that can be strengthened by heat treatment and coated with a ceramic layer offering time-certain resorption of a medical device. This in vitro study shows that these treatments do not result in cytotoxicity. Both heat-treated (HT) and HT + ceramic-coated (sol–gel) coupons demonstrated more than 70% viability. Thus, these processing steps are likely to be useful in producing biocompatible, resorbable implants that incorporate our Mg–1.2Zn–0.5Ca–0.5Mn alloy.

36 MATERIALS SCIENCE↗

NASA NTRS1984

A test to verify the biocompatibility of a method for plant culture in a microgravity environment

We report a pioneering attempt to use the NASA Shuttle Orbiter Middeck locker facility to acquire data on plant growth in near weightlessness. The information was needed to confirm the suitability of a plant culture system to be used in an experiment scheduled for the first Spacelab mission. The test was designed to measure germination and early seedling growth in a series of soil mixtures covering a range of water contents. Empirical determination of growth dependence on moisture content was required because both in theory and from Soviet flight experience it seemed possible that the dependence function in near weightlessness could be critically different from what we had measured on Earth. Such a difference could invalidate the future test in Spacelab 1 of gravity dependence of the differential growth process, circumnutation. After two failed attempts sufficient measurements were obtained from the third Shuttle Orbiter flight test to confirm the biocompatibility of the plant culture system--viz. soil moisture content variations had the same effect in near weightlessness as at 1 g. A number of supplemental observations about middeck locker conditions in Shuttle flight are presented. These may prove helpful to would-be experimenters who will plan to take advantage of future Shuttle flight opportunities for biological research.

Non-NASA Center↗

NASA NTRS2012

Biocompatible, biodegradable polymer-based, lighter than or light as water scaffolds for tissue engineering and methods for preparation and use thereof

Scaffolds for tissue engineering prepared from biocompatible, biodegradable polymer-based, lighter than or light as water microcarriers and designed for cell culturing in vitro in a rotating bioreactor are provided. Methods for preparation and use of these scaffolds as tissue engineering devices are also provided.

Laurencin, Cato T.↗

NASA NTRS2017

Biocompatible Capsules and Methods of Making

Embodiments of the invention include capsules for containing medical implants and delivery systems for release of active biological substances into a host body. Delivery systems comprise a capsule comprising an interior enclosed by walls, and a source of active biological substances enclosed within the capsule interior, wherein the active biological substances are free to diffuse across the capsule walls. The capsule walls comprise a continuous mesh of biocompatible fibers and a seal region where two capsule walls overlap. The interior of the capsule is substantially isolated from the medium surrounding the capsule, except for diffusion of at least one species of molecule between the capsule interior and the ambient medium, and prevents cell migration into or out of the capsule. Methods for preparing and using the capsules and delivery systems are provided.

Loftus, David J.↗

DOE OSTI2022

Biocompatible surface functionalization architecture for a diamond quantum sensor

Significance Diamond-based quantum sensing enables nanoscale measurements of biological systems with unprecedented sensitivity. Potential applications of this emerging technology range from the investigation of fundamental biological processes to the development of next-generation medical diagnostics devices. One of the main challenges faced by bioquantum sensing is the need to interface quantum sensors with biological target systems. Specifically, such an interface needs to maintain the highly fragile quantum states of our sensor and at the same time be able to fish intact biomolecules out of solution and immobilize them on our quantum sensor surface. Our work overcomes these challenges by combining tools from quantum engineering, single-molecule biophysics, and material processing.

77 NANOSCIENCE AND NANOTECHNOLOGY↗

NASA NTRS2014

Ground Testing of the EMCS Seed Cassette for Biocompatibility with the Cellular Slime Mold, Dictyostelium Discoideum

The European Modular Cultivation System, EMCS, was developed by ESA for plant experiments. To expand the use of flight verified hardware for various model organisms, we performed ground experiments to determine whether ARC EMCS Seed Cassettes could be adapted for use with cellular slime mold for future space flight experiments. Dictyostelium is a cellular slime mold that can exist both as a single-celled independent organism and as a part of a multicellular colony which functions as a unit (pseudoplasmodium). Under certain stress conditions, individual amoebae will aggregate to form multicellular structures. Developmental pathways are very similar to those found in Eukaryotic organisms, making this a uniquely interesting organism for use in genetic studies. Dictyostelium has been used as a genetic model organism for prior space flight experiments. Due to the formation of spores that are resistant to unfavorable conditions such as desiccation, Dictyostelium is also a good candidate for use in the EMCS Seed Cassettes. The growth substratum in the cassettes is a gridded polyether sulfone (PES) membrane. A blotter beneath the PES membranes contains dried growth medium. The goals of this study were to (1) verify that Dictyostelium are capable of normal growth and development on PES membranes, (2) develop a method for dehydration of Dictyostelium spores with successful recovery and development after rehydration, and (3) successful mock rehydration experiments in cassettes. Our results show normal developmental progression in two strains of Dictyostelium discoideum on PES membranes with a bacterial food source. We have successfully performed a mock rehydration of spores with developmental progression from aggregation to slug formation, and production of morphologically normal spores within 9 days of rehydration. Our results indicate that experiments on the ISS using the slime mold, Dictyostelium discoideum could potentially be performed in the flight verified hardware of the EMCS ARC Seed Cassettes.

biocompatibility↗

NASA NTRS2014

Ground Testing of the EMCS Seed Cassette for Biocompatibility with the Tardigrade, Hypsibius dujardini

The European Modular Cultivation System, EMCS, was developed by ESA for plant experiments. We performed ground testing to determine whether ARC EMCS seed cassettes could be adapted for use with tardigrades for future spaceflight experiments. Tardigrades (water bears) are small invertebrates that enter the tun state in response to desiccation or other environmental stresses. Tardigrade tuns have suspended metabolism and have been shown to be survive exposure to space vacuum, high pressure, temperature and other stresses. For spaceflight experiments using the EMCS, the organisms ideally must be able to survive desiccation and storage in the cassette at ambient temperature for several weeks prior to the initiation of the experiment by the infusion of water to the cassette during spaceflight. The ability of tardigrades to survive extremes by entering the tun state make them ideal candidates for growth experiments in the EMCS cassettes. The growth substratum in the cassettes is a gridded polyether sulfone (PES) membrane. A blotter beneath the PES membrane contains dried growth medium. The goals of our study were to (1) determine whether tardigrades survive and reproduce on PES membranes, (2) develop a consistent method for dehydration of the tardigrades with high recovery rates upon rehydration, (3) to determine an appropriate food source for the tardigrades that can also be dehydrated/rehydrated and (4) successful mock rehydration experiment in cassettes with appropriate food source. We present results that show successful multigenerational growth of tardigrades on PES membranes with a variety of wet food sources. We have successfully performed a mock rehydration with tardigrades and at least one candidate food, protonema of the moss Polytrichum, that supports multigenerational growth and whose spores germinate quickly enough to match tardigrade feeding patterns post rehydration. Our results indicate that experiments on the ISS using the tardigrade, Hypsibius dujardini and other similar species could successfully be performed in the flight verified hardware of the EMCS seed cassettes.

EMCS s↗

DOE OSTI2023

Cellulose Nanocrystals are a Renewable and Biocompatible Nanocarrier of Agrochemicals Directly to Plant Cells

More sustainable agricultural practices are critical to meeting humanity's food needs while minimizing adverse environmental impacts. Engineered nanomaterials used as nanocarriers promise to reduce the volume of agrochemicals required for crop production but concerns about nanocontamination of agricultural products necessitate the discovery of naturally occurring alternatives. Here, in this study, plant‐derived cellulose nanocrystals (CNC) as a “green” alternative to man‐made nanomaterials for the economical delivery of agrochemicals to plants are suggested. Using confocal microscopy and fluorescently labeled CNC, it is demonstrated that CNC can successfully penetrate the plant cell wall and enter cells without causing any negative effects on the overall plant phenotype, genome, and metabolome. The efficiency of CNC to deliver chemicals is demonstrated through in vitro tests involving CNC covalently conjugated with 2,4‐dichlorophenoxyacetic acid (2,4‐D). Plant cell culture experiments confirmed that CNC can be used as a 2,4‐D nanocarrier and reduces the volume of plant growth regulators needed to cultivate plant cells. This work creates a new platform for cyclical agricultural practices where CNC extracted from agricultural waste can be used for the direct delivery of agrochemicals to crops, thereby reducing the environmental burden created by both agricultural waste and excess herbicides.

Cellulose nanocrystals↗

DOE OSTI2020

Bright Infrared‐to‐Ultraviolet/Visible Upconversion in Small Alkaline Earth‐Based Nanoparticles with Biocompatible CaF 2 Shells

Abstract Upconverting nanoparticles (UCNPs) are promising candidates for photon‐driven reactions, including light‐triggered drug delivery, photodynamic therapy, and photocatalysis. Herein, we investigate the NIR‐to‐UV/visible emission of sub‐15 nm alkaline‐earth rare‐earth fluoride UCNPs (M 1− x Ln x F 2+ x , MLnF) with a CaF 2 shell. We synthesize 8 alkaline‐earth host materials doped with Yb 3+ and Tm 3+ , with alkaline‐earth (M) spanning Ca, Sr, and Ba, MgSr, CaSr, CaBa, SrBa, and CaSrBa. We explore UCNP composition, size, and lanthanide doping‐dependent emission, focusing on upconversion quantum yield (UCQY) and UV emission. UCQY values of 2.46 % at 250 W cm −2 are achieved with 14.5 nm SrLuF@CaF 2 particles, with 7.3 % of total emission in the UV. In 10.9 nm SrYbF:1 %Tm 3+ @CaF 2 particles, UV emission increased to 9.9 % with UCQY at 1.14 %. We demonstrate dye degradation under NIR illumination using SrYbF:1 %Tm 3+ @CaF 2 , highlighting the efficiency of these UCNPs and their ability to trigger photoprocesses.

Fischer, Stefan↗

DOE OSTI2020