Silk-based blood stabilization for diagnostics

Abstract

Advanced personalized medical diagnostics depend on the availability of high-quality biological samples. These are typically biofluids, such as blood, saliva, or urine; and their collection and storage is critical to obtain reliable results. Without proper temperature regulation, protein biomarkers in particular can degrade rapidly in blood samples, an effect that ultimately compromises the quality and reliability of laboratory tests. Here, we present the use of silk fibroin as a solid matrix to encapsulate blood analytes, protecting them from thermally induced damage that could be encountered during nonrefrigerated transportation or freeze-thaw cycles. Blood samples are recovered by simple dissolution of the silk matrix in water. This process is demonstrated to be compatible with a number of immunoassays and provides enhanced sample preservation in comparison with traditional air-drying paper approaches. Additional processing can remediate interactions with conformational structures of the silk protein to further enhance blood stabilization and recovery. This approach can provide expanded utility for remote collection of blood and other biospecimens empowering new modalities of temperature-independent remote diagnostics.lood contains a variety of proteins, enzymes, lipids, metabolites, and peptides, which can be interrogated as biomarkers for health screening, monitoring, and diagnostics. The integrity of these blood components and thus the quality of information attained from their analysis is determined by the storage conditions from sampling until analysis, or the so-called pre-analytical phase (1, 2). This phase often includes time-consuming processing steps and the requirement for a continuous cold storage. Without temperature regulation, blood-derived biospecimens degrade quickly, accounting for up to 67% of all laboratory testing errors (2, 3). Further, when blood-derived materials are frozen, decreases in thermodynamic free energy and unfavorable ice crystal-protein interactions (4) can occur during subsequent thawing (5, 6), which can further compromise analyte integrity as a gold-standard methodology.As an alternative route, blood and blood derivatives can be dried via newer approaches such as isothermal vitrification (7), lyophilization (8), or on silica chips (9). Isothermal vitrification and lyophilization are inherently resource-intensive techniques and thus not suitable for field use. Silica chips are designed for enrichment of selected fractions of the low-molecular-weight serum proteome, but are not broadly protective at elevated temperature (10). An inexpensive alternative used since the 1960s are dried blood spots (DBS) (11), a paper card system which captures blood components among cellulose fibers as the water phase evaporates. These drying measures decrease sample weight by >90%, thus decreasing transport burden, and in theory can enhance long-term sample stability by decreasing water-dependent analyte degradation caused by hydrolysis and enzyme activity (12). Unfortunately, DBS stored in ...

Engineering the Future of Silk Materials through Advanced Manufacturing

“…In the past two decades, silk has undergone a technological revolution with a large body of research focused on engineering new material formats using the natural protein (extracted from the gland, or from silk fibers) as well as genetically engineered ones (especially, recombinant spider silk proteins). Silk materials have been fabricated into various material formats for biomedical applications with successful demonstrations in tissue engineering, drug stabilization and controlled delivery, and implantable medical devices . Furthermore, silk has also been widely used in flexible electronics, optical and photonic devices owing to the great flexibility and optical properties.…”

Comparative Study of Strain‐Dependent Structural Changes of Silkworm Silks: Insight into the Structural Origin of Strain‐Stiffening

“…In contrast to synthetic polymers based on chemical reactions, silkworm silk is a protein‐based material produced by silkworms at ambient conditions in an all‐aqueous reaction environment. Silk is thus produced in an environment‐friendly process, and due to biocompatibility and mechanical features shows potential for developing healthcare products, biomedical devices, and biosensors . The extraordinary mechanical properties of silk originate from the unique highly repetitive sequence in fibroin, along molecular self‐assembly and organization at nanoscale .…”

Modular flow chamber for engineering bone marrow architecture and function

“…Moreover, silk was functionalized with ECM components that are expressed in the physiological bone marrow structure [7]. Importantly, it was previously shown that silk preserves the activity of the encapsulated molecules [13,15,16]. …”

“…Finally, a third system, made by PDMS, was developed with a wide array of von Willebrand Factor-coated micropillars supposed to act as anchors on Mks, allowing them to extend proplatelets under a hydrodynamic shear [11]. Compared to these systems for platelet production, a critical feature of our flow chamber is the use of natural silk protein biomaterial to leverage its versatility such as programmable mechanical properties, and surface binding of growth factors and ECM components, while retaining their bioavailability [13,16]. In our previous BM model we used silk tubes and sponges to recreate the vascular niche where Mks release platelets [16].…”