Polyhydroxyalkanoates (PHAs) are excellent candidate biomaterials due to their exceptional biodegradability and biocompatibility. However, PHAs need to have tunable hydrophilicity, chemical ...functionalities, and appropriate hydrolytic stability to expand their therapeutic applications towards more advanced areas. In this Tutorial Review, we present the most recent progress in the synthetic strategies of PHA-based water soluble polymers, including the functionalisation of PHAs with polar functional groups and the block/graft copolymerization of PHAs with hydrophilic components in various polymeric architectures. These chemically modified water soluble PHAs have significant impact on materials engineering and show great value in the fulfilment of smart biomaterials in emerging areas. The applications of water soluble PHAs in controlled drug release, cancer therapy, DNA/siRNA delivery and tissue engineering in new aspects are discussed. In addition, water soluble PHA monomer production will be briefly introduced, with emphasis on its bio-significance in medical physiology and the therapeutic effect in the treatment of diseases.
Polyhydroxyalkanoates (PHAs) are excellent candidate biomaterials due to their exceptional biodegradability and biocompatibility.
The development of hybrid biomaterials has been attracting great attention in the design of materials for biomedicine. The nanosized level of inorganic and organic or even bioactive components can be ...combined into a single material by this approach, which has created entirely new advanced compositions with truly unique properties for drug delivery. The recent advances in using hybrid nanovehicles as remotely controlled therapeutic delivery carriers are summarized with respect to different nanostructures, including hybrid host–guest nanoconjugates, micelles, nanogels, core–shell nanoparticles, liposomes, mesoporous silica, and hollow nanoconstructions. In addition, the controlled release of guest molecules from these hybrid nanovehicles in response to various remote stimuli such as alternating magnetic field, near infrared, or ultrasound triggers is further summarized to introduce the different mechanisms of remotely triggered release behavior. Through proper chemical functionalization, the hybrid nanovehicle system can be further endowed with many new properties toward specific biomedical applications.
The development of hybrid biomaterials has been attracting great attention in the design of materials for biomedicine. The most recent advances of using hybrid nanovehicles as remotely controlled therapeutic delivery system are summarized.
Coacervation is a process during which a homogeneous aqueous solution undergoes liquid–liquid phase separation, giving rise to two immiscible liquid phases composed of a colloid‐rich coacervate phase ...in equilibrium with a colloid‐poor phase simultaneously. Recent attempts to develop complex coacervation from macromolecular self‐assemblies have diversified a large group of novel coacervate‐related materials with sophisticated properties and emerging applications. In this review, the most recent progress in the design strategies of macromolecular complex coacervation is discussed with respect to different key parameters, including macromolecular structure, mixing ratio, ionic strength, pH, and temperature, etc. Furthermore, the applications of these multiple‐functional coacervate materials, oriented toward advanced encapsulation, are further summarized into several active domains in wastewater treatment, protein purification, food formulation, underwater adhesives, drug delivery, and cellular mimics. Finally, perspectives and future challenges related to the further advancement of macromolecular complex coacervates are proposed.
A comprehensive overview of recent work on complex coacervation from macromolecular assemblies, with a focus on coacervate mechanics, design strategies, and influence factors on their formation, is provided. Furthermore, recent achievements on representative applications of coacervate‐based materials in a broad range of fields are highlighted.
Polylactide (PLA) has been receiving significant attention in biopolymer research due to its excellent biodegradability, biocompatibility and sustainability. The mass production of PLA from renewable ...agricultural resources has delved this green material as a top alternative to replace the petroleum-based conventional polymers. However, the inherent weaknesses of PLA in its raw state such as brittleness, low heat distortion temperature and recrystallization rate, as well as the inadequate crystallization ability and degree after fast processing have limited the competitive edge of PLA over traditional synthetic plastics in industrial use or for biomedical applications. Being different from other types of biodegradable polymers, the diverse isomeric forms of PLA have provided great opportunities for thermal and mechanical enhancement through stereocomplexation formation. In this review, we present the most recent development in thermal and mechanical enhancement of PLA via stereocomplexation of PLA in different polymeric systems, including enantiomeric PLA homopolymers, PLA-based block and graft copolymers, as well as enantiomeric PLA materials having unique architectures such as cyclic, star, dendritic and comb-shaped. Insightful discussion on the influence of crystal structure and intermolecular interactions between PLLA and PDLA in the different polymeric systems on the enhanced performance of the resultant materials are provided. The enhanced PLA with diverse functions oriented toward engineering materials and their biosignificance in different areas are also covered in this review.
Due to the low-cost, facile processability and the capability of producing large areas of flexible thin films, organic optoelectronic materials have been considered among the most promising materials ...in the past two decades in both academic research and industry applications. Particularly, the incorporation of polyhedral oligomeric silsesquioxanes (POSSs) to develop high performance organic optoelectronic materials and the fabrication of these sophisticated materials into highly efficient devices are of significant interest because of the unique hybrid structures and physical properties of POSS. In this review, we present the recent advances in the development of POSS-based organic optoelectronic materials and devices, including organic light-emitting diodes (OLEDs), liquid crystal display, sensors and electrochromic devices. In addition, the insights into the uniqueness of POSS in microstructure, confined size effect, and their different organic substituents in the enhancement of the optoelectronic performance are illustrated. Finally, perspectives and challenges related to the further advancement of POSS-based organic optoelectronic materials are discussed, followed by the proposed design considerations to address the challenges that we will face in the future.
Due to the unique hybrid structures and physical properties of polyhedral oligomeric silsesquioxanes (POSSs), hybridation with POSS has been demonstrated to be an important approach to build high-performance organic optoelectronic materials for applications in organic light-emitting diodes (OLEDs), liquid crystal display, sensors and electrochromic devices.
Biomaterials is an exciting and dynamic field, which uses a collection of diverse materials to achieve desired biological responses. While there is constant evolution and innovation in materials with ...time, biomaterials research has been hampered by the relatively long development period required. In recent years, driven by the need to accelerate materials development, the applications of machine learning in materials science has progressed in leaps and bounds. The combination of machine learning with high‐throughput theoretical predictions and high‐throughput experiments (HTE) has shifted the traditional Edisonian (trial and error) paradigm to a data‐driven paradigm. In this review, each type of biomaterial and their key properties and use cases are systematically discussed, followed by how machine learning can be applied in the development and design process. The discussions are classified according to various types of materials used including polymers, metals, ceramics, and nanomaterials, and implants using additive manufacturing. Last, the current gaps and potential of machine learning to further aid biomaterials discovery and application are also discussed.
The advancement of machine learning (ML) in materials science has progressed in leaps and bounds and has made a big impact into biomaterials research, ranging from discovery of bioactive chemical moieties, screening and optimization of material properties, to developing materials that interface better with biological systems. There is still untapped potential to integrate with ML for the next frontier in biomaterials.
A highly tunable nanoparticle (NP) system with multifunctionalities was developed as drug nanocarrier via a facile layer-by-layer (LbL) stereocomplex (SC) self-assembly of enantiomeric poly(l-lactic ...acid) (PLLA) and poly(d-lactic acid) (PDLA) in solution using silica-coated magnetite (Fe3O4@SiO2) as template. The poly(lactide) (PLA) SC coated NPs (Fe3O4@SiO2@-SC) were further endowed with different stimuli-responsiveness by controlling the outermost layer coatings with respective pH-sensitive poly(lactic acid)-poly(2-dimethylaminoethyl methacrylate) (PLA-D) and temperature-sensitive poly(lactic acid)-poly(N-isopropylacrylamide) (PLA-N) diblock copolymers to yield Fe3O4@SiO2@SC-D and Fe3O4@SiO2@SC-N NPs, respectively, while the superparamagnetic properties of Fe3O4 were maintained. TEM images show a clearly resolved core–shell structure with a silica layer and sequential PLA SC co/polymer coating layers in the respective NPs. The well-designed NPs possess a size distribution in a range of 220–270 nm and high magnetization of 70.8−72.1 emu/g Fe3O4. More importantly, a drug release study from the as-constructed stimuli-responsive NPs exhibited sustained release profiles and the rates of release can be tuned by variation of external environments. Further cytotoxicity and cell culture studies revealed that PLA SC coated NPs possessed good cell biocompatibility and the doxorubicin (DOX)-loaded NPs showed enhanced drug delivery efficiency toward MCF-7 cancer cells. Together with the strong magnetic sensitivity, the developed hybrid NPs demonstrate a great potential of control over the drug release at a targeted site. The developed coating method can be further optimized to finely tune the nanocarrier size and operating range of pHs and temperatures for in vivo applications.
While small hydrophilic therapeutic molecules have proved to be exceptionally effective in curing diseases, their
in vivo
efficacy remains low. Small molecule therapeutics infused
in vivo
result in ...uncontrolled bio-distribution that causes dilution and unwanted side effects. Therefore, global research to search for ideal carriers for small molecule therapeutics has gained attention seeking to increase efficiency of targeting desired cells. Liposomes are one class of nanocarriers that could encapsulate both hydrophilic and lipophilic small molecule therapeutics, protect them against physiological degradation and deliver them into targeted cells. In this review, studies done from the past up to the present are summarized, and various methods and mechanisms for encapsulation of small therapeutic molecules in liposomes for targeted delivery and triggered release, as well as their potential in the clinical uses, will be discussed.
In this review, various methods and mechanisms for encapsulation of small therapeutic molecules in liposomes for targeted delivery and triggered release, as well as their potential in the clinical uses, are discussed.
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