Multiplexed in vivo screening of biological samples

Biocompatibility is an essential aspect of the medical device industry. Biocompatibility testing ensures that devices do not contain materials or substances that could be harmful to patients during initial use or over the course of time. Biocompatibility tests can be used to detect many possible negative side effects of a product on patient. These may include effects on cells and physiological systems, tissue irritation and inflammation, immunological and allergic reactions and the possibility of cellular mutations leading to cancer. Email:marketing@medicilon.com.cn Web:www.medicilon.com

Microfabricated platforms can be used to study a heterogeneous panel of biosamples in a realistic in vivo setting. The platform can be formed of a polymer (e.g., a hydrogel) and can be constructed for implantation into an animal host for in vivo testing. The platform can have a plurality of testing regions therein that are constructed to allow exposure of the testing region to the host stroma when implanted in vivo. For example, the microfabricated platform can be used for screening different cancer cell-lines (e.g., to identify which cell line responds to an anti-cancer drug) or for screening different biomaterials (e.g., to identify a composition with ideal host response for a specific implantable device).

The present application claims the benefit of U.S. Provisional Application No. 61/531,573, filed Sep. 6, 2011, which is hereby incorporated by reference herein in its entirety.

The present application relates generally to testing of biological samples, and, more particularly, to systems, methods, and devices for multiplexed in vivo screening of biological samples, for example, for cancer drug screening or material biocompatibility testing.

Monolayer culture systems are used by pharmaceuticals and research labs to investigate the efficacy of anti-cancer therapeutic agents. However, the inability of the monolayer system to mimic tumor microenvironment leads to inaccurate prediction of drug efficacy in vivo. Often, promising lead compounds fail in the later phases of clinical trials despite initially encouraging results. Compared to other therapeutic areas, there is a particularly high attrition rate for anti-cancer drugs. Indeed, in recent years there have been a large number of unsuccessful clinical trials, with only 8% of drug candidates which enter Phase I trials actually reaching the bedside.

Individual anti-cancer compounds may only be effective for cells with specific genotypes. Efficacy studies to determine which genotypes a particular drug is effective against are performed at a relatively low throughput in animal models. A single compound is thus screened against one genotype per animal. While animal models, such as transgenic mice and xenograft models, can serve as a promising tool for preclinical studies, the low throughput of these systems and the inability to test large number of cell-lines limits their potential to capture the genomic heterogeneity of cancer. It is therefore logistically challenging to identify the subgroups of responsive cancer cells for the developed rationally targeted drugs.

In one or more embodiments, the testing regions may be individual chambers holding respective tumor spheroids therein. A membrane layer may retain the tumor spheroid within the interior of each chamber while allowing stromal cell interaction with the tumor spheroid. The tumors may be of different genotypes from each other so as to allow simultaneous testing of multiple genotypes in a single host animal. An anti-cancer drug (or any other type of therapeutic device or agent) can be given to the host animal while (or before) the platform is implanted therein, thereby subjecting each of the tumor genotypes to the same host environment at the same time. The construction and arrangement of the platform and the testing regions may be such that the cross-talk between adjacent testing regions (e.g., unintended or undesirable interactions between tumor cells of different genotypes) is minimized or at least reduced.

In one or more embodiments, the testing regions may be individual biomaterials formed on or in the platform. A surface of the individual biomaterials can be exposed to the host stroma for interaction therewith. The individual biomaterials can have different compositions and/or materials from each other so as to allow simultaneous testing of multiple types in a single host animal. The platform can be implanted in the host animal and left to interact with the host for a period of time. Biocompatibility (or other desired characteristics of the implanted biomaterials) can be ascertained for each biomaterial by appropriate inspection and analysis of the extracted platform.

In one or more embodiments, a method of screening multiple biological samples in vivo can include providing a platform (e.g., of polymer) having a plurality of testing regions thereon. A separate one of the biological samples can be placed in each of the testing regions. The method can further include implanting the platform into a host animal such that each of the biological samples interacts with stroma cells of the host animal. The method can also include removing the platform from the host animal to evaluate said testing regions. The method can further include, after the implanting, administering a cancer drug to the host animal.

The testing regions can be arrayed in two dimensions across the platform, for example, as a circular or rectangular array. The number of testing regions on the platform can be at least 20. The testing regions can be configured and arranged such that cross-talk between the biological samples while implanted in the host animal is prevented or at least reduced. The biological samples can be tumor spheroids. Each tumor spheroid can be a different genotype. Alternatively or additionally, the biological samples can be materials for biocompatibility testing. For example, the materials can include hydrogels.

The platform can include a plurality of microfluidic channels. Each of the microfluidic channels can be connected to a respective one of the testing regions. Placing the platform can include flowing cancer cells through the microfluidic channels to load each chamber and forming in each chamber a tumor spheroid from the cancer cells therein. Each chamber can include a membrane layer with pores therein. The membrane layer can be constructed to retain the tumor spheroid in the chamber. The pores can be sized and shaped to allow infiltration of host animal stroma cells after the implanting. The chamber can have a diameter of 500 μm or less and a height of 300 μm or less. The membrane layer can have a thickness of 20 μm or more.

In one or more embodiments of the disclosed subject matter, a device for screening multiple biological samples in vivo can include a platform member. The platform member can have a plurality of testing regions thereon. Each of the testing regions can be configured to hold a different biological sample for interaction in vivo with stroma cells when implanted into a host animal. The platform can also include isolating portions arranged between adjacent testing regions such that fluid and/or material cannot pass from one testing region to another testing region without contacting the host animal stroma cells when implanted into the host animal.