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Soybean proteins have found uses in different nonfoodapplicationsdue to their interesting properties. We report on the kinetics andextent of adsorption on silica and cellulose surfaces of glycininand β-conglycinin, the main proteins present in soy. Quartzcrystal microgravimetry (QCM) experiments indicate that soy protein adsorptionis strongly affected by changes in the physicochemical environment.The affinity of glycinin and the mass adsorbed on silica and celluloseincreases (by ca. 13 and 89%, respectively) with solution ionic strength(as it increases from 0 to 100 mM NaCl) due to screening of electrostaticinteractions. In contrast, β-conglycinin adsorbs on the samesubstrates to a lower extent and the addition of electrolyte reducesadsorption (by 25 and 57%, respectively). The addition of 10 mM 2-mercaptoethanol,a denaturing agent, reduces the adsorption of both proteins with asignificant effect for glycinin. This observation is explained bythe cleavage of disulfide bonds which allows unfolding of the moleculesand promotes dissociation into subunits that favors more compact adsorbedlayer structures. In addition, adsorption of glycinin onto cellulosedecreases with lowering the pH from neutral to pH 3 due to dissociationof the macromolecules, resulting in flatter adsorbed layers. The respectiveadsorption isotherms fit a Langmuir model and QCM shifts in energydissipation and frequency reveal multiple-step kinetic processes indicativeof changes in adlayer structure. [ABSTRACT FROM AUTHOR]

As a larger elderly human population is expected worldwide in the next 30 years, the occurrence of aging-associated illnesses will also be increased. The use of prosthetic devices by this population is currently important and will be even more dramatic in the near future. Hence, the design of prosthetic devices able to reduce some of the problems associated with the use of current components, such as stress shielding, reduced mobility, infection, discomfort, etc., becomes relevant. The use of additive manufacturing (AM) and the design fabrication of self-supported cellular structures in the biomedical area have opened up important opportunities for controlling the physical and mechanical properties of hip implants, resulting in specific benefits for the patients. Different studies have reported the development of hip prosthetic designs employing AM, although there are still opportunities for improvement when it comes to customized design and tuning of the physical and mechanical properties of such implants. This work shows the design and manufacture by AM of a personalized stainless-steel partial hip implant using tomography data and self-supported triply periodic minimal surface (TPMS) cell structures; the design considers dimensional criteria established by international standards. By employing tomography data, the external dimensions of the implant were established and the bone density of a specific patient was calculated; the density and mechanical properties in compression of the implant were modulated by employing an internal gyroid-type cell structure. Using such a cell structure, the patient's bone density was emulated; also, the mechanical properties of the implant were fine-tuned in order to make them comparable to those reported for the bone tissue replaced by the prosthesis. The implant design and manufacturing methodology developed in this work considered the clinical condition of a specific patient and can be reproduced and adjusted for different types of bone tissue qualities for specific clinical requirements., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)

Deposition of hydrophobic wood extractives and representative model compounds, on the surface of cellulose prior to enzymatic hydrolysis was found to either enhance or inhibit the action of cellulase enzymes. The effect of these compounds was correlated with their chemical structure, which may in part explain the differential effects observed between softwood and hardwood extractives. Specifically, the addition of sterol, enhanced enzymatic hydrolysis of microcrystalline cellulose by 54%, whereas the addition of a triglyceride could inhibit the hydrolysis by 49%. The effects of the different extractives' could be explained by considering their Hansen solubility parameters. The amphiphilic and/or hydrophobic character of model extractives was found to be the variable that affected the deposition of extractives on cellulose surfaces and the eventual adsorption of cellulolytic enzymes on it. The observed beneficial effects of extractives are likely related to a reduction in the irreversible binding of the enzymes on the cellulose surface.

Modification of the wetting behavior of hydrophobic surfaces is essential in a variety of materials, including textiles and membranes that require control of fluid interactions, adhesion, transport processes, sensing, etc. This investigation examines the enhancement of wettability of an important class of textile materials, viz., polypropylene (PP) fibers, by surface adsorption of different proteins from soybeans, including soy flour, isolate,glycinin, and β-conglycinin. Detailed investigations of soy adsorption from aqueous solution (pH 7.4, 25 °C) on polypropylene thin films is carried out using quartz crystal microbalance (QCM) and surface plasmon resonance (SPR). A significant amount of protein adsorbs onto the PP surfaces primarily due to hydrophobic interactions. We establish that adsorption of a cationic surfactant, dioctadecyldimethylammonium bromide (DODA) onto PP surfaces prior to the protein deposition dramatically enhances its adsorption. The adsorption of proteins from native (PBS buffer, pH 7.4, 25 °C) and denatured conditions (PBS buffer, pH 7.4, 95 °C) onto DODA-treated PP leads to a high coverage of the proteins on the PP surface as confirmed by a significant improvement in water wettability. A shift in the contact angle from 128° to completely wettable surfaces (≈0°) is observed and confirmed by imaging experiments conducted with fluorescence tags. Furthermore, the results from wicking tests indicate that hydrophobic PP nonwovens absorb a significant amount of water after protein treatment, i.e., the PP-modified surfaces become completely hydrophilic.

Lignins are used often in formulations involving proteins but little is known about the surface interactions between these important biomacromolecules. In this work, we investigate the interactions at the solid-liquid interface of lignin with the two main proteins in soy, glycinin (11S) and β-conglycinin (7S). The extent of adsorption of 11S and 7S onto lignin films and the degree of hydration of the interfacial layers is quantified via Quartz crystal microgravimetry (QCM) and surface plasmon resonance (SPR). Solution ionic strength and protein denaturation (2-mercaptoethanol and urea) critically affect the adsorption process as protein molecules undergo conformational changes and their hydrophobic or hydrophilic amino acid residues interact with the surrounding medium. In general, the adsorption of the undenatured proteins onto lignin is more extensive compared to that of the denatured biomolecules and a large amount of water is coupled to the adsorbed molecules. The reduction in water contact angle after protein adsorption (by ~40° and 35° for undenatured 11S and 7S, respectively) is explained by strong nonspecific interactions between soy proteins and lignin.