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Applications of Antiviral Nanoparticles in Cancer Therapy
Published in Devarajan Thangadurai, Saher Islam, Charles Oluwaseun Adetunji, Viral and Antiviral Nanomaterials, 2022
Anusha Konatala, Sai Brahma Penugonda, Fain Parackel, Sudhakar Pola
Various synthetic polymers, including poly(lactic-co-glycolic) acid (PLGA), polyanhydrides, and dextrans, as well as natural polymers, including elastin-like polypeptides, have been used for preparing nanoparticles. The PEG-cloaked drugs have higher bioavailability compared to naked drugs.
Order Cirlivirales
Published in Paul Pumpens, Peter Pushko, Philippe Le Mercier, Virus-Like Particles, 2022
Paul Pumpens, Peter Pushko, Philippe Le Mercier
In plants, the full-length BFDV Cap and a truncated Cap (ΔN40) were transiently expressed in tobacco Nicotiana benthamiana as fusions to elastin-like polypeptide (Duvenage et al. 2013). These two proteins were C-terminally fused to the elastin-like polypeptides of different lengths, 140 or 255 aa residues, in order to increase expression levels and to provide a simple means of purification, while the self-assembly of the products into VLPs, which could be potentially affected by long fusions, was not assessed. Regnard et al. (2017) published the first report of the plant-made full-length BFDV Cap assembling into the VLPs, and the putative pseudovirions were suggested to further efficacy studies as putative vaccines. Thus, the virion-like Cap VLPs were successfully produced in N. benthamiana, albeit at relatively low yield. Moreover, the VLPs spontaneously incorporated amplicon DNA produced from the replicating bean yellow dwarf virus (BeYDV) plant vector (Regnard et al. 2017).
A ‘Biomaterial Cookbook’: Biochemically Patterned Substrate to Promote and Control Vascularisation in Vitro and in Vivo
Published in Harishkumar Madhyastha, Durgesh Nandini Chauhan, Nanopharmaceuticals in Regenerative Medicine, 2022
Katie M. Kilgour, Brendan L. Turner, Augustus Adams, Stefano Menegatti, Michael A. Daniele
Finally, synthetic peptides represent special building blocks for tissue scaffold engineering, being biocompatible, biodegradable, bioactive, and low-toxicity protein mimetics (Du, Zhou, Shi, & Xu, 2015; Liu, Zhang, Zhu, Liu, & Chen, 2019). Peptides can assemble into hydrogels either physically, by forming a network of hydrogen bonds and electrostatic and hydrophobic interactions, or chemically, via site-selective crosslinking (Liu et al., 2019). Lastly, they can be manufactured in high volumes, affordably, and with no variability. This makes peptides ideal biomaterials for tissue engineering and wound healing (Barbosa & Martins, 2017). In this context, elastin-like polypeptides are of particular interest, as they feature a thermo-responsive phase behaviour, wherein the sol–gel transition temperature and the mechanical properties of the resulting hydrogel depend on the ELP’s amino acid sequence (Urry, 1997). Engineered ELPs fused with cell-binding peptide domains or signalling proteins have been expressed and utilised as building blocks to construct different angiogenic substrates (e.g., gels, films, or fibres) with tuned ELP: water ratio, temperature, and composition of the growth medium. Crosslinked ELP hydrogels have been constructed to present cell-binding motifs such as fibronectin-derived REDV, VEGF-derived QK, laminin-derived IKVAV, and integrin-binding RGD to act as ECM mimetics. Cai et al. developed ELP-based hydrogels encapsulating HUVECs and functionalised with the cell-binding RGD sequence and the VEGF mimetic QK peptide; the hydrogels maintained nearly 100% of cell viability along with significantly enhanced cell proliferation and 3D outgrowth (Cai, Dinh, & Heilshorn, 2014). Another study, by Santos et al., focused on cell- and factor-free hybrid hydrogels constructed with ELPs, polyethylene glycol (PEG), and the self-assembling IKVAV peptide and evaluated their ability to induce angiogenesis and innervation in vivo (dos Santos et al., 2019); notably, the hydrogel hosted a larger density of vessels 26 days post-implantation when the IKVAV peptide was present, indicating that integration of bioactive peptides in natural biomaterials provides a route towards long-term stability in pro-angiogenic scaffolds.
Emerging pharmacologic interventions for pre-eclampsia treatment
Published in Expert Opinion on Therapeutic Targets, 2022
Xiao Zhang, Yue Chen, Dongli Sun, Xiaojun Zhu, Xia Ying, Yao Yao, Weidong Fei, Caihong Zheng
Elastin-like polypeptides (ELPs) are bioengineered proteins derived from human elastin that are not immunogenic. ELPs can be easily modified as the length and sequence of repeating amino acid motifs can be altered to achieve an optimal molecular size and allow further chemical attachment. More importantly, ELPs are broadly distributed and accumulate within the placental labyrinth without fetal exposure [187]. Logue et al., in 2017 [188] developed a biopolymer-stabilized ELP-VEGF fusion protein that could relieve pre-eclamptic symptoms in a rat model and prevent fetal exposure to exogenous VEGF. Additionally, researchers constructed an ELP drug delivery system (SynB1-ELP-p50i) consisting of an ELP, a cell-penetrating peptide called SynB1, and the NF-κB inhibitor peptide p50i. This well-designed delivery system also had a relatively long plasma half-life and prevented placental transfer [189]. Given the reversible aggregation ability of ELPs, Abdelghani et al., in 2021 [190] designed a pH-responsive ELP diblock copolymer that disassembles under mildly acidic conditions. Such pH-responsiveness-based construction represents another promising strategy for pre-eclamptic treatment, as the microenvironment outside trophoblast cells has relatively low pH because of hypoxia-induced lactate production [191].
Current advances in cell therapeutics: a biomacromolecules application perspective
Published in Expert Opinion on Drug Delivery, 2022
Samson A. Adeyemi, Yahya E. Choonara
Elastin is a bio-synthetic biomacromolecule synthesized from human elastin sequences as the backbone[105]. Elastin-Like Polypeptides (ELPs) are produced from a plasmid-borne gene in Escherichia coli [106] which are then extracted by purifying the cell lysates and characterized by large monomers with repeating units. Based on this bio-engineering technique Rodriguez-Cabello and co-workers [107] coined the term elastin-like ‘recombinamer’ (ELR). The VPGVG pentapeptide repeat is a widely investigated ELR family and represents the most ubiquitous sequence found in human elastin naturally. Several other ELRs have been manufactured from the VPGVG repeat by replacing the fourth amino acid with other naturally occurring amino acids, except proline. When heated, ELRs respond to heat and show a reversible sol-gel transition interphase. At transition temperature, they form a random-coil conformation and when heated, the chain folds hydrophobically to form a uniform b-spiral stabilized structure. The polymer molecular weight, its concentration in solution and composition of the amino acids control the transition temperature and can be monitored to stabilize between room and body temperature. In addition, it is possible to engineer this biomacromolecule to accommodate biodegradation sequences [108] or add specific cell adhesion motifs [109]. For instance, Costa and co-workers [110,111] added chitosan as a polycation to a negatively charged ELR having the RGD motifs to synthesize microcapsules using a layer-by-layer technique for application in the transport of bioactive agents and cells in tissue engineering.
Polymers, responsiveness and cancer therapy
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2019
Anil M. Pethe, Khushwant S. Yadav
The elastin-like polypeptides were engineered and broadly explored for smart drug delivery and targeting systems [28,29]. The elastin pentapeptide materials repeat Val-Pro-Gly-Xaa-Gly sequence which were developed for showcasing LCST behaviour around 40 °C by the alteration of these repeat sequences and inclusion of both the oligoalanine and oligoglycine residues. The transition temperatures had the outline of the target that the particles might frame on ultrasound induction of hyperthermia, thereby locallytargeting drugs to an ELP backbone. The thermal transition of homopolypeptides took place over a narrow range and was completely reversible for a (Val5-Ala2-Gly3)150 polypeptide. The beginning of LCST was between 40 °C and 42 °C. The preparation of block co-polymers happened with more complex thermal transitions indicating a range of intermediate species formed as differential blocks aggregated. The particles of 40–100 nm were created for both homo- and co-polymers over the LCST with proposed favourable use in disease treatment that was inferable from the aggregation of particles of this size in tumour tissues. A similar group has detailed the utilization of ELP-doxorubicin conjugates for temperature which intervened tumour suppression. A promising start in drug targeting is the local aggression of the ELP-conjugates in tumour cells by responsive synthetic polypeptides.