Biomedical subjects

Stacey A Maskarinec

Publications and source records attributed to Stacey A Maskarinec.

3 recordsLinked to original sources

PubMed2005

Protein engineering approaches to biomaterials design.

Biomaterials play crucial roles in reconstructive surgery, tissue engineering and regenerative medicine. Protein engineering offers powerful solutions to the challenges posed by the creation of well-defined, multifunctional materials that guide cell and tissue behavior. Especially challenging is the complex interplay between mechanical and biological properties in determining the success or failure of biomaterials designed for clinical use.

Biocompatible Materials↗

PubMed2005

Membrane sealing by polymers.

An intact cell membrane serves as a barrier, controlling the traffic of materials going into and out of the cell. When the integrity of the membrane is compromised, its transport barrier function is also disrupted, leaving the cell vulnerable to necrosis. It has been shown that triblock copolymer surfactants can help seal structurally damaged membranes, arresting the leakage of intracellular materials. Using model lipid monolayers along with concurrent Langmuir isotherm and fluorescence microscopy measurements as well as surface X-ray scattering techniques, the nature of the interaction between lipids and a particular family of triblock copolymers in the form poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) is examined. The polymer is found to selectively insert into membranes where the lipid packing density is below that of an intact cell membrane, thus localizing its sealing effect on damaged portions of the membrane. The inserted polymer is "squeezed out" of the lipid film when the lipid packing density is increased, suggesting a mechanism for the cell to be rid of the polymer when the membrane integrity is restored.

Animals↗

PubMed2002

Direct observation of poloxamer 188 insertion into lipid monolayers.

P188, a triblock copolymer of the form poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) helps seal electroporated cell membranes, arresting the leakage of intracellular materials from the damaged cells. To explore the nature of the interaction between P188 and cell membranes, we have constructed a model system that assesses the ability of P188 to insert into lipid monolayers. Using concurrent Langmuir isotherm and fluorescence microscopy measurements, we find that P188 changes the phase behavior and morphology of the monolayers. P188 inserts into both dipalmitoylphosphatidlycholine and dipalmitoylphosphatidylglycerol monolayers at surface pressures equal to and lower than approximately 22 mN/m at 30 degrees C; this pressure corresponds to the maximal surface pressure attained by P188 on a pure water subphase. Similar results for the two phospholipids indicate that P188 insertion is not influenced by headgroup electrostatics. Because the equivalent surface pressure of a normal bilayer is on the order of 30 mN/m, the lack of P188 insertion above 22 mN/m further suggests the poloxamer selectively adsorbs into damaged portions of electroporated membranes, thereby localizing its effect. P188 is also found to be "squeezed out" of the monolayers at high surface pressures, suggesting a mechanism for the cell to be rid of the poloxamer when the membrane is restored.

Cell Membrane↗