The Utilisation of Hydrogels for iPSC-Cardiomyocyte Research

Cardiac fibroblasts’ (FBs) and cardiomyocytes’ (CMs) behaviour and morphology are influenced by their environment such as remodelling of the myocardium, thus highlighting the importance of biomaterial substrates in cell culture. Biomaterials have emerged as important tools for the development of physiological models, due to the range of adaptable properties of these materials, such as degradability and biocompatibility. Biomaterial hydrogels can act as alternative substrates for cellular studies, which have been particularly key to the progression of the cardiovascular field. This review will focus on the role of hydrogels in cardiac research, specifically the use of natural and synthetic biomaterials such as hyaluronic acid, polydimethylsiloxane and polyethylene glycol for culturing induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs). The ability to fine-tune mechanical properties such as stiffness and the versatility of biomaterials is assessed, alongside applications of hydrogels with iPSC-CMs. Natural hydrogels often display higher biocompatibility with iPSC-CMs but often degrade quicker, whereas synthetic hydrogels can be modified to facilitate cell attachment and decrease degradation rates. iPSC-CM structure and electrophysiology can be assessed on natural and synthetic hydrogels, often resolving issues such as immaturity of iPSC-CMs. Biomaterial hydrogels can thus provide a more physiological model of the cardiac extracellular matrix compared to traditional 2D models, with the cardiac field expansively utilising hydrogels to recapitulate disease conditions such as stiffness, encourage alignment of iPSC-CMs and facilitate further model development such as engineered heart tissues (EHTs)

2D Hierarchical Microbarcodes with Expanded Storage Capacity for Optical Multiplex and Information Encryption

The design of nanosegregated fluorescent tags/barcodes by geometrical patterning with precise dimensions and hierarchies could integrate multilevel optical information within one carrier and enhance microsized barcoding techniques for ultrahigh-density optical data storage and encryption. However, precise control of the spatial distribution in micro/nanosized matrices intrinsically limits the accessible barcoding applications in terms of material design and construction. Here, crystallization forces are leveraged to enable a rapid, programmable molecular packing and rapid epitaxial growth of fluorescent units in 2D via crystallization-driven self-assembly. The fluorescence encoding density, scalability, information storage capacity, and decoding techniques of the robust 2D polymeric barcoding platform are explored systematically. These results provide both a theoretical and an experimental foundation for expanding the fluorescence storage capacity, which is a longstanding challenge in state-of-the-art microbarcoding techniques and establish a generalized and adaptable coding platform for high-throughput analysis and optical multiplexing

Elastomeric polyamide biomaterials with stereochemically tuneable mechanical properties and shape memory

Abstract: Biocompatible polymers are widely used in tissue engineering and biomedical device applications. However, few biomaterials are suitable for use as long-term implants and these examples usually possess limited property scope, can be difficult to process, and are non-responsive to external stimuli. Here, we report a class of easily processable polyamides with stereocontrolled mechanical properties and high-fidelity shape memory behaviour. We synthesise these materials using the efficient nucleophilic thiol-yne reaction between a dipropiolamide and dithiol to yield an α,β − unsaturated carbonyl moiety along the polymer backbone. By rationally exploiting reaction conditions, the alkene stereochemistry is modulated between 35–82% cis content and the stereochemistry dictates the bulk material properties such as tensile strength, modulus, and glass transition. Further access to materials possessing a broader range of thermal and mechanical properties is accomplished by polymerising a variety of commercially available dithiols with the dipropiolamide monomer

Upaya Hukum Dalam Menyelesaikan Perkara Pidana Dengan Negara Lain Menurut Undang-undang Nomor 1 Tahun 2006

Tujuan dilakukan penelitian ini adalah untuk mengetahui bagaimana upaya hukum yang dilakukan negara Republik Indonesia menyelesaikan tindak pidana dengan negara lain dan bagaimana syarat-syarat pemberian bantuan untuk menyelesaikan perkara pidana kepada negara lain. Ruang lingkup penulisan ini adalah pada disiplin ilmu hukum, maka penulisan ini merupakan bagian dari penulisan hukum kepustakaan yakni dengan cara meneliti bahan pustaka atau yang dinamakan penelitian hukum normatif dapat disimpulkan, bahwa: 1. Upaya hukum yang dilakukan untuk negara Republik Indonesia menyelesaikan perkara pidana dengan negara asing, yaitu dengan membuat kesepakatan dalam bentuk perjanjian bilateral maupun multilateral dengan negara asing dan berdasarkan prinsip timbal Balik melalui saluran diplomatik serta pembentukan peraturan Perundang-undangan nasional yang mengatur bantuan timbal Balik dalam masalah pidana. Adanya perjanjian Internasional yaitu dapat memberikan jaminan kepastian hukum yang melandasi hubungan kerjasama Internasional dalam penyelesaian perkara pidana. 2. Syarat-syarat pemberian bantuan untuk menyelesaikan perkara pidana kepada negara lain, yaitu: setiap negara asing dapat mengajukan permintaan Bantuan kepada Pemerintah Republik Indonesia. Negara asing dapat mengajukan permintaan Bantuan secara langsung atau dapat memilih melalui saluran diplomatik

The sustainable materials roadmap

Over the past 150 years, our ability to produce and transform engineered materials has been responsible for our current high standards of living, especially in developed economies. However, we must carefully think of the effects our addiction to creating and using materials at this fast rate will have on the future generations. The way we currently make and use materials detrimentally affects the planet Earth, creating many severe environmental problems. It affects the next generations by putting in danger the future of the economy, energy, and climate. We are at the point where something must drastically change, and it must change now. We must create more sustainable materials alternatives using natural raw materials and inspiration from nature while making sure not to deplete important resources, i.e. in competition with the food chain supply. We must use less materials, eliminate the use of toxic materials and create a circular materials economy where reuse and recycle are priorities. We must develop sustainable methods for materials recycling and encourage design for disassembly. We must look across the whole materials life cycle from raw resources till end of life and apply thorough life cycle assessments (LCAs) based on reliable and relevant data to quantify sustainability. We need to seriously start thinking of where our future materials will come from and how could we track them, given that we are confronted with resource scarcity and geographical constrains. This is particularly important for the development of new and sustainable energy technologies, key to our transition to net zero. Currently 'critical materials' are central components of sustainable energy systems because they are the best performing. A few examples include the permanent magnets based on rare earth metals (Dy, Nd, Pr) used in wind turbines, Li and Co in Li-ion batteries, Pt and Ir in fuel cells and electrolysers, Si in solar cells just to mention a few. These materials are classified as 'critical' by the European Union and Department of Energy. Except in sustainable energy, materials are also key components in packaging, construction, and textile industry along with many other industrial sectors. This roadmap authored by prominent researchers working across disciplines in the very important field of sustainable materials is intended to highlight the outstanding issues that must be addressed and provide an insight into the pathways towards solving them adopted by the sustainable materials community. In compiling this roadmap, we hope to aid the development of the wider sustainable materials research community, providing a guide for academia, industry, government, and funding agencies in this critically important and rapidly developing research space which is key to future sustainability.journal articl

A renewably sourced, circular photopolymer resin for additive manufacturing

The additive manufacturing of photopolymer resins by means of vat photopolymerization enables the rapid fabrication of bespoke 3D-printed parts. Advances in methodology have continually improved resolution and manufacturing speed, yet both the process design and resin technology have remained largely consistent since its inception in the 1980s1. Liquid resin formulations, which are composed of reactive monomers and/or oligomers containing (meth)acrylates and epoxides, rapidly photopolymerize to create crosslinked polymer networks on exposure to a light stimulus in the presence of a photoinitiator2. These resin components are mostly obtained from petroleum feedstocks, although recent progress has been made through the derivatization of renewable biomass3,4,5,6 and the introduction of hydrolytically degradable bonds7,8,9. However, the resulting materials are still akin to conventional crosslinked rubbers and thermosets, thus limiting the recyclability of printed parts. At present, no existing photopolymer resin can be depolymerized and directly re-used in a circular, closed-loop pathway. Here we describe a photopolymer resin platform derived entirely from renewable lipoates that can be 3D-printed into high-resolution parts, efficiently deconstructed and subsequently reprinted in a circular manner. Previous inefficiencies with methods using internal dynamic covalent bonds10,11,12,13,14,15,16,17 to recycle and reprint 3D-printed photopolymers are resolved by exchanging conventional (meth)acrylates for dynamic cyclic disulfide species in lipoates. The lipoate resin platform is highly modular, whereby the composition and network architecture can be tuned to access printed materials with varied thermal and mechanical properties that are comparable to several commercial acrylic resins

Designing Thermally Stable Organocatalysts for Poly(ethylene terephthalate) Synthesis: Toward a One-Pot, Closed-Loop Chemical Recycling System for PET

Organocatalysis provides robust methodology to furnish “greener” routes to polymer synthesis. However, the application toward the synthesis of aromatic polymers via step-growth polymerization is an area that justifies more investigation, as a consequence of the poor thermal stability of many organic catalysts and the high reaction temperatures commonly required. In this study, thermally stable organic salts consisting of an organic base and an organic acid were explored to understand key elements required for the bulk synthesis of poly(ethylene terephthalate) (PET) at 270 °C. The ΔpKa values of the salts played an important role in the thermal stability such that the salts with higher ΔpKa values showed higher stability because of the strong acid–base interactions. The 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) salts with high ΔpKa values (≥16.9) showed the best catalytic activity among the investigated salts in terms of both low amounts of side reactions and discoloration. The thermal and chemical stability of the salts also affected the polymer properties. Dimerization side reactions that lead to defects in the polymer backbone were found to occur more readily in salts containing strong acids as components, particularly as the ΔpKa between the acid–base components decreased. The discoloration of the PET sample was also correlated to the thermal stability of the organic salt catalyst, with a lower stability generally leading to enhanced discoloration likely due to decomposition of base components. Polymerization–depolymerization cycles were also investigated with the TBD:p-toluenesulfonic acid (TSA) salt and the feasibility of simple, closed-loop recycling of PET with the system was established

Nickel-Catalyzed Suzuki Polycondensation for Controlled Synthesis of Ester-Functionalized Conjugated Polymers

Controlled synthesis of conjugated polymers with functional side chains is of great importance, affording well-defined optoelectronic materials possessing enhanced stability and tunability as compared to their alkyl-substituted counterparts. Herein, a chain-growth Suzuki polycondensation of an ester-functionalized thiophene is described using commercially available nickel precatalysts. Model compound studies were used to identify suitable catalysts, and these experiments provided guidance for the polymerization of the ester-substituted monomer. This is the first report of nickel-catalyzed Suzuki cross-coupling for catalyst-transfer polycondensation, and to further illustrate the versatility of this method, block and alternating copolymers with 3-hexyl­thiophene were synthesized. The presented protocol should serve as an entry point into the synthesis of other electron-deficient polymers and donor–acceptor copolymers with controlled molecular weights and low dispersity

Stability and Reactivity of 1,3-Benzothiaphosphole: Metalation and Diels–Alder Chemistry

The synthesis and functionalization of the parent 1,3-benzothiaphosphole is reported. The phosphole could not be isolated, but the compound could be manipulated in solution to produce several new phosphorus compounds. Metalation of the 2-position using lithium diisopropylamide proceeded smoothly according to ³¹P NMR spectroscopy, and quenching with trimethylsilyl chloride resulted in the desired 2-(trimethylsilyl)-1,3-benzothiaphosphole. The PC bond of the thiaphosphole was also explored as a dienophile in Diels–Alder reactions with isoprene, 2,3-dimethylbutadiene, 2,3-dibenzylbutadiene, and cyclopentadiene. The fused-ring structures were fully characterized, and a solid-state molecular structure of the 2,3-dimethylbutadiene cycloadduct was obtained. Residual dipolar coupling (RDC) NMR experiments were used to assign major and minor products for the isoprene and cyclopentadiene adducts

Stability and Reactivity of 1,3-Benzothiaphosphole: Metalation and Diels–Alder Chemistry

The synthesis and functionalization of the parent 1,3-benzothiaphosphole is reported. The phosphole could not be isolated, but the compound could be manipulated in solution to produce several new phosphorus compounds. Metalation of the 2-position using lithium diisopropylamide proceeded smoothly according to ³¹P NMR spectroscopy, and quenching with trimethylsilyl chloride resulted in the desired 2-(trimethylsilyl)-1,3-benzothiaphosphole. The PC bond of the thiaphosphole was also explored as a dienophile in Diels–Alder reactions with isoprene, 2,3-dimethylbutadiene, 2,3-dibenzylbutadiene, and cyclopentadiene. The fused-ring structures were fully characterized, and a solid-state molecular structure of the 2,3-dimethylbutadiene cycloadduct was obtained. Residual dipolar coupling (RDC) NMR experiments were used to assign major and minor products for the isoprene and cyclopentadiene adducts