Biology subjects

Horowitz, L.

Publications and source records attributed to Horowitz, L..

3 recordsLinked to original sources

bioRxiv2025

BIOPRINTING OF MICRODISSECTED TUMOR CUBOIDS IN HYDROGELS

Microscale tumor models made from microdissected tumors that retain much of the original human tumor microenvironment (TME) are emerging as an alternative to preclinical animal models. We have introduced a drug testing approach that utilizes regularly-cut, cuboidal-shaped microdissected tissues, or "cuboids," as a way to maximize creation of microtissues from scarce biopsy materials. However, microtissues (e.g., cuboids, organoids, spheroids, etc.) can be difficult to place in precise locations, especially in applications that require their culture in hydrogels. Here, using cuboids from mouse tumor models, we demonstrate a simple bioprinting strategy for precise placement and immobilization of cuboids in hydrogel. We use a commercial bioprinter to bioprint-containing hydrogel into arrays of small hydrogel dots containing cuboids, or "cuboid dots," either onto a Transwell insert or into traps on a microplate. The hydrogel serves to immobilize the cuboids in place and provides a matrix to support cuboid viability. We demonstrate proof-of-concept applications for cancer drug testing and for protein profiling analysis. This approach will enable interface of cuboids with other devices, such as on top of a sensor or in a microfluidic platform. Furthermore, this automated process of dispensing and localizing cuboids (or other microtissue formats such as spheroids or organoids) could further their application to drug discovery and personalized medicine. TOC Graphic O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=109 SRC="FIGDIR/small/671932v1_ufig1.gif" ALT="Figure 1"> View larger version (30K): org.highwire.dtl.DTLVardef@e1d020org.highwire.dtl.DTLVardef@1271797org.highwire.dtl.DTLVardef@17de734org.highwire.dtl.DTLVardef@d62b97_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2024

MICROMANIPULATION OF LIVE MICRODISSECTED TISSUES WITH A LOW-COST INTEGRATED ROBOTIC PLATFORM

The scarcity of human biopsies available for drug testing is a paramount challenge for developing new therapeutics, disease models, and personalized treatments. Microtechnologies that combine the microscale manipulation of tissues and fluids offer the exciting possibility of miniaturizing both disease models and drug testing workflows on scarce human biopsies. Unfortunately, these technologies presently require microfluidic devices or robotic dispensers that are not widely accessible. We have rapidly-prototyped an inexpensive platform based on an off-the-shelf robot that can microfluidically manipulate live microtissues into/out of culture plates without using complicated accessories such as microscopes or pneumatic controllers. The robot integrates complex functions with a simple, cost-effective and compact construction, allowing placement inside a tissue culture hood for sterile workflows. We demonstrated a proof-of-concept cancer drug evaluation workflow of potential clinical utility using patient tumor biopsies with multiple drugs on 384-well plates. Our user-friendly, low-cost platform promises to make drug testing of microtissues broadly accessible to pharmaceutical, clinical, and biological laboratories. TeaserA low-cost robot for handling microtissues and catalyzing their use in cancer drug evaluation and personalized oncology.

bioengineering↗

bioRxiv2024

Label-Free, Real-Time Monitoring of Cytochrome C Responses to Drugs in Microdissected Tumor Biopsies with a Multi-Well Aptasensor Platform

Functional assays on intact tumor biopsies can potentially complement and extend genomics-based approaches for precision oncology, drug testing, and organs-on-chips cancer disease models by capturing key determinants of therapeutic response, such as tissue architecture, tumor heterogeneity, and the tumor microenvironment. Currently, most of these assays rely on fluorescent labeling, a semi-quantitative method best suited to be a single-time-point terminal assay or labor-intensive terminal immunostaining analysis. Here, we report integrated aptamer electrochemical sensors for on-chip, real-time monitoring of increases of cytochrome C, a cell death indicator, from intact microdissected tissues with high affinity and specificity. The platform features a multi-well sensor layout and a multiplexed electronic setup. The aptasensors measure increases in cytochrome C in the supernatant of mouse or human microdissected tumors after exposure to various drug treatments. Since the aptamer probe can be easily exchanged to recognize different targets, the platform could be adapted for multiplexed monitoring of various biomarkers, providing critical information on the tumor and its microenvironment. This approach could not only help develop more advanced cancer disease models but also apply to other complex in vitro disease models, such as organs-on-chips and organoids.

bioengineering↗