A nanoparticle-assembled photonic crystal (PC) array was used to detect single nucleotide polymorphism (SNP). The assay platform with PC nanostructure enhanced the fluorescent signal from nanoparticle-hybridized DNA complexes due to phase matching of excitation and emission. Nanoparticles coupled with probe DNA were trapped into nanowells in an array by using an electrophoretic particle entrapment system. The PC/DNA assay platform was able to identify a 1 base pair (bp) difference in synthesized nucleotide sequences that mimicked the mutation seen in a feline model of human autosomal dominant polycystic kidney disease (PKD) with a sensitivity of 0.9 fg/mL (50 aM)-sensitivity, which corresponds to 30 oligos/array. The reliability of the PC/DNA assay platform to detect SNP in a real sample was demonstrated by using genomic DNA (gDNA) extracted from the urine and blood of two PKD^- wild type and three PKD positive cats. The standard curves for PKD positive (PKD⁺) and negative (PKD^-) DNA were created using two feline-urine samples. An additional three urine samples were analyzed in a similar fashion and showed satisfactory agreement with the standard curve, confirming the presence of the mutation in affected urine. The limit of detection (LOD) was 0.005 ng/mL which corresponds to 6 fg per array for gDNA in urine and blood. The PC system demonstrated the ability to detect a number of genome equivalents for the PKD SNP that was very similar to the results reported with real time polymerase chain reaction (PCR). The favorable comparison with quantitative PCR suggests that the PC technology may find application well beyond the detection of the PKD SNP, into areas where a simple, cheap and portable nucleic acid analysis is desirable.

Glioblastoma multiforme (GBM) is the most lethal primary brain tumor characterized by high cellular and molecular heterogeneity, hypervascularization, and innate drug resistance. Cellular components and extracellular matrix (ECM) are the two primary sources of heterogeneity in GBM. Here, biomimetic tri-regional GBM models with tumor regions, acellular ECM regions, and an endothelial region with regional stiffnesses patterned corresponding to the GBM stroma, pathological or normal brain parenchyma, and brain capillaries, are developed. Patient-derived GBM cells, human endothelial cells, and hyaluronic acid derivatives are used to generate a species-matched and biochemically relevant microenvironment. This in vitro study demonstrates that biophysical cues are involved in various tumor cell behaviors and angiogenic potentials and promote different molecular subtypes of GBM. The stiff models are enriched in the mesenchymal subtype, exhibit diffuse invasion of tumor cells, and induce protruding angiogenesis and higher drug resistance to temozolomide. Meanwhile, the soft models demonstrate enrichment in the classical subtype and support expansive cell growth. The three-dimensional bioprinting technology utilized in this study enables rapid, flexible, and reproducible patient-specific GBM modeling with biophysical heterogeneity that can be employed by future studies as a tunable system to interrogate GBM disease mechanisms and screen drug compounds.

Background

Weight gain and associated metabolic complications are increasingly prevalent among people with HIV (PWH). Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are incretin-based therapies for diabetes and weight management that have been shown to result in substantial weight loss; however, studies of their effects in PWH are limited.

Methods

A retrospective single-center cohort study was conducted among PWH who were taking GLP-1RAs at UC San Diego Owen Clinic between 2/1/2021 to 2/1/2023. Baseline clinical data were collected and changes in weight, body mass index (BMI), and hemoglobin A1C (A1C) before starting GLP-1RAs compared to the most recent clinic visit were calculated (with a minimum of 3 months follow-up time required). Logistic regression was performed to identify variables associated with >5% of total body weight loss.

Results

A total of 225 patients received on average 13 months of GLP-1RA therapy, with 85 (37.8%) achieving the maximum GLP-1RA dose. GLP-1RA therapy resulted, on average, in a loss of 5.4 kg, decrease in BMI by 1.8 kg/m2, and decrease in A1C by 0.6%. In the multivariable analysis, higher baseline BMI [OR 1.10 (1.03-1.16)], treatment duration of GLP-1RA therapy greater than 6 months [OR 3.12 (1.49-6.49], and use of tirzepatide [OR 5.46 (1.44-20.76)] were significantly more likely to be associated with >5% weight loss.

Conclusions

Use of GLP-1RAs led to declines in weight, BMI, and hemoglobin A1C among PWH and offers an additional strategy to address weight gain and diabetes.