Biology subjects

Golden, E.

Publications and source records attributed to Golden, E..

3 recordsLinked to original sources

bioRxiv2025

3D-Printed Titanium Implants with Bioactive Peptide-polysaccharide Scaffolds for Personalized Bone Reconstruction

Large bone defects caused by trauma, tumor resection, or congenital abnormalities remain a major clinical challenge. Standard titanium implants are widely used due to their strength and biocompatibility, but their bioinert surfaces often lead to poor osseointegration. The emergence of 3D printing has enabled patient-specific titanium implants with tailored architecture and mechanical properties. However, these constructs still lack the bioactivity required for robust and spatially uniform bone integration, particularly within the implant core. To address this limitation, we developed a bioactive, cell-free strategy that integrates porous titanium implants with a nanofibrillar peptide-hyaluronic acid scaffold, delivered either as a hydrogel or in lyophilized form. The scaffold exhibited enhanced enzymatic stability and supported osteoblast-like cell adhesion in vitro. In a rabbit calvarial critical-size bone defect model, scaffold-integrated implants significantly outperformed inert controls, with hydrogel integration nearly doubling inner bone volume and improving trabecular architecture. Histological analysis confirmed enhanced bone-implant integration, active periosteum, healthy marrow, and reduced inflammation. This acellular, growth-factor-free approach combines the structural precision of titanium with the regenerative potential of ECM-mimicking scaffolds, offering a translatable pathway for personalized skeletal repair.

bioengineering↗

bioRxiv2021

Parametric modulators of sex-biased conditioned fear responding

Pavlovian fear conditioning is a widely used behavioral paradigm for studying associative learning in rodents. Despite early recognition that subjects may engage in a variety of both conditioned and unconditioned responses, the last several decades have seen the field narrow its focus to measure freezing as the sole indicator of conditioned fear. We previously reported that female rats were more likely than males to engage in darting, an escape-like conditioned response that is associated with heightened shock reactivity. To determine how experimental parameters contribute to the frequency of darting in both males and females, we manipulated factors such as chamber size, shock intensity, and number of trials. To better capture fear-related behavioral repertoires in our animals, we developed ScaredyRat, an open-source custom Python tool that analyzes Noldus Ethovision-generated raw data files to identify Darters and quantify both conditioned and unconditioned responses. We find that like freezing, conditioned darting occurrences scale with experimental alterations. While most darting occurs in females, we find that with an extended training protocol, darting can emerge in males as well. Collectively, our data suggest that darting reflects a behavioral switch in conditioned responding that is a product of both an individual animals sex, shock reactivity, and experimental parameters, underscoring the need for careful consideration of sex as a biological variable in classic learning paradigms.

animal behavior and cognition↗

bioRxiv2021

Antibody responses to SARS-CoV-2 mRNA vaccines are detectable in saliva

Vaccines are critical for curtailing the COVID-19 pandemic (1, 2). In the USA, two highly protective mRNA vaccines are available: BNT162b2 from Pfizer/BioNTech and mRNA-1273 from Moderna (3, 4). These vaccines induce antibodies to the SARS-CoV-2 S-protein, including neutralizing antibodies (NAbs) predominantly directed against the Receptor Binding Domain (RBD) (1-4). Serum NAbs are induced at modest levels within [~]1 week of the first dose, but their titers are strongly boosted by a second dose at 3 (BNT162b2) or 4 weeks (mRNA-1273) (3, 4). SARS-CoV-2 is most commonly transmitted nasally or orally and infects cells in the mucosae of the respiratory and to some extent also the gastrointestinal tract (5). Although serum NAbs may be a correlate of protection against COVID-19, mucosal antibodies might directly prevent or limit virus acquisition by the nasal, oral and conjunctival routes (5). Whether the mRNA vaccines induce mucosal immunity has not been studied. Here, we report that antibodies to the S-protein and its RBD are present in saliva samples from mRNA-vaccinated healthcare workers (HCW). Within 1-2 weeks after their second dose, 37/37 and 8/8 recipients of the Pfizer and Moderna vaccines, respectively, had S-protein IgG antibodies in their saliva, while IgA was detected in a substantial proportion. These observations may be relevant to vaccine-mediated protection from SARS-CoV-2 infection and disease.

microbiology↗