Biotechnology eJournal最新文献

{"title":"Long Carrier Diffusion Length in Two-Dimensional Lead Halide Perovskite Single Crystals","authors":"Shreetu Shrestha, Xinxin Li, H. Tsai, Cheng-Hung Hou, Hsin-Hsiang Huang, D. Ghosh, J. Shyue, Leeyih Wang, S. Tretiak, Xuedan Ma, W. Nie","doi":"10.2139/ssrn.3891067","DOIUrl":"https://doi.org/10.2139/ssrn.3891067","url":null,"abstract":"SUMMARYRuddlesden-Popper (RP) perovskites are two-dimensional semiconductors for high performance devices. In this work, we report a long in-plane charge carrier diffusion length in 2D RP perovskite single crystals probed by scanning photocurrent microscopy. Carrier diffusion lengths of 7~14 µm are observed when the number of PbI6-2 octahedrons between organic spacers increases from 1 to 3. By detailed light intensity and electric field-dependent photocurrent measurements, we attribute the observed long diffusion length to the dominating dissociated free carrier transport. This is further validated by time-resolved photoluminescence measurements where the decay lifetime increases in the presence of an electric field. From our experiments, we conclude that the in-plane transport in RP perovskites is efficient because of the partial free carrier generation overcoming strong excitonic effects. Our results suggest that semiconducting devices fabricated from RP perovskite single crystals can be as efficient as their 3D counterparts.","PeriodicalId":446238,"journal":{"name":"Biotechnology eJournal","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123944700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biomaterials via Peptide Assembly: Design, Characterization, and Application in Tissue Engineering","authors":"Vincent P Gray, C. Amelung, I. J. Duti, Emma G. Laudermilch, R. Letteri, K. Lampe","doi":"10.2139/ssrn.3878342","DOIUrl":"https://doi.org/10.2139/ssrn.3878342","url":null,"abstract":"A core challenge in biomaterials, with both fundamental significance and technological relevance, concerns the rational design of bioactive microenvironments. Designed properly, peptides can undergo supramolecular assembly into dynamic, physical hydrogels that mimic the mechanical, topological, and biochemical features of native tissue microenvironments. The relatively facile, inexpensive, and automatable preparation of peptides coupled with low batch-to-batch variability motivates the expanded use of assembling peptide hydrogels for biomedical applications. Integral to realizing dynamic peptide assemblies as functional biomaterials for tissue engineering is an understanding of the molecular and macroscopic features that govern assembly, morphology, and biological interactions. In this review, we first discuss the design of assembling peptides, including primary structure (sequence), secondary structure (e.g., α-helix and β-sheets), and molecular interactions that facilitate assembly into multiscale materials with desired properties. Next, we describe characterization tools for elucidating molecular structure and interactions, morphology, bulk properties, and biological functionality. Understanding of these characterization methods enables researchers to access a variety of approaches in this ever-expanding field. Finally, we discuss the biological properties and applications of peptide-based biomaterials for engineering several important tissues. By connecting molecular features and mechanisms of assembling peptides to the material and biological properties, we aim to guide the design and characterization of peptide-based biomaterials for tissue engineering and regenerative medicine. STATEMENT OF SIGNIFICANCE: Well-defined topological and mechanical properties of assembled peptides can be used to direct biological responses. Engineering peptide-based extracellular matrices offers immense opportunity for regenerative medicine and tissue engineering. Here we review the molecular-scale features of assembling peptides that result in useful extracellular matrix properties and desired cell interactions. Aiming to inspire researchers approaching this challenge from both the peptide biomaterial design and tissue engineering perspectives, we present characterization tools for understanding the connection between peptide structure and properties and highlight the use of peptide-based biomaterials in neural, orthopedic, cardiac, muscular, and immune engineering applications.","PeriodicalId":446238,"journal":{"name":"Biotechnology eJournal","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115706575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of Abandoned Mine Wastes Disposal Techniques in Malawi: A Concept of Circular Economy","authors":"Horris K. Nangulama","doi":"10.31219/osf.io/vyshg","DOIUrl":"https://doi.org/10.31219/osf.io/vyshg","url":null,"abstract":"Non-operational mines mostly constitute of significant quantities of valuable mineral resources within tailings and waste rock that can be disposed properly using innovative techniques. Proper waste disposal techniques do not only reduce the need for new mines to be developed but also have broad beneficial results on mining environmental impact. This paper presents a solution on abandoned mine wastes in Malawi. Malawi government wants to embrace techniques on former mine waste recycling operations that incentivize investment. Thus, this analysis proposes abandoned mine waste recycling technique for Malawi government to adopt. Recycling technique, as one of the current direction methods, is determined for adoption. The powerful impacts of recycling principles in turning Malawi’s abandoned mine wastes into beneficial products that can support and sustain its economy are given. The concept of circular economy is prominently in the picture, so the wastes can be changed into wealth and other created benefits.","PeriodicalId":446238,"journal":{"name":"Biotechnology eJournal","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123447432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tumor Vasculature-Targeting Nanomedicines","authors":"Ying Zhang, Jingni He","doi":"10.2139/ssrn.3818058","DOIUrl":"https://doi.org/10.2139/ssrn.3818058","url":null,"abstract":"Uncontrolled tumor growth and subsequent distant metastasis are highly dependent on an adequate nutrient supply from tumor blood vessels, which have relatively different pathophysiological characteristics from those of normal vasculature. Obviously, strategies targeting tumor vasculature, such as anti-angiogenic drugs and vascular disrupting agents, are attractive methods for cancer therapy. However, the off-target effects and high dose administration of these drug regimens critically restrict their clinical applications. In recent years, nanomedicines focused on tumor vasculature have been shown to be superior to traditional therapeutic methods and do not induce side effects. This review will first highlight the recent development of tumor vasculature-targeting nanomedicines from the following four aspects: 1) angiogenesis-inhibiting nanomedicines (AINs); 2) vasculature-disrupting nanomedicines (VDNs); 3) vasculature infarction nanomedicines (VINs); and 4) vasculature-regulating nanomedicines (VRNs). Furthermore, the design principles, limitations, and future directions are also discussed. STATEMENT OF SIGNIFICANCE: : Based on the essential roles of tumor blood vessels, the therapeutic strategies targeting tumor vasculature have exhibited good clinical therapeutic outcomes. However, poor patient adherence to free drug administration limits their clinical usage. Nanomedicines have great potential to overcome the abovementioned obstacle. This review summarizes the tumor-vasculature targeting nanomedicines from four aspects: 1) angiogenesis-inhibiting nanomedicines (AINs); 2) vasculature-disrupting nanomedicines (VDNs); 3) vasculature infarction nanomedicines (VINs); and 4) vasculature regulating nanomedicines (VRNs). In addition, this review provides perspectives on this research field.","PeriodicalId":446238,"journal":{"name":"Biotechnology eJournal","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128203320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Quantitative Analysis of Cell Bridging Kinetics on a Scaffold Using Computer Vision Algorithms","authors":"Matthew Lanaro, Maximilion P. Mclaughlin, M. Simpson, P. Buenzli, C. Wong, M. Allenby, M. Woodruff","doi":"10.2139/ssrn.3818056","DOIUrl":"https://doi.org/10.2139/ssrn.3818056","url":null,"abstract":"Tissue engineering involves the seeding of cells into a structural scaffolding to regenerate the architecture of damaged or diseased tissue. To effectively design a scaffold, an understanding of how cells collectively sense and react to the geometry of their local environment is needed. Advances in the development of melt electro-writing have allowed micron and submicron polymeric fibres to be accurately printed into porous, complex and three-dimensional structures. By using melt electrowriting, we created a geometrically relevant in vitro scaffold model to study cellular spatial-temporal kinetics. These scaffolds were paired with custom computer vision algorithms to investigate cell nuclei, cell membrane actin and scaffold fibres over different pore sizes (200-600 µm) and time points (28 days). We find that cells proliferated much faster in the smaller (200 µm) pores which halved the time until confluence versus larger (500 and 600 µm) pores. Our analysis of stained actin fibres revealed that cells were highly aligned to the fibres and the leading edge of the pore filling front, and we found that cells behind the leading edge were not aligned in any particular direction. This study provides a systematic understanding of cellular spatial temporal kinetics within a 3D in vitro model to inform the design of more effective synthetic tissue engineering scaffolds for tissue regeneration. STATEMENT OF SIGNIFICANCE: : Advances in the development of melt electro-writing have allowed micron and submicron polymeric fibres to be accurately printed into porous, complex and three-dimensional structures. By using melt electrowriting, we created a geometrically relevant in vitro model to study cellular spatial-temporal kinetics to provide a systematic understanding of cellular spatial temporal kinetics within a 3D in vitro model. The insights presented in this work help to inform the design of more effective synthetic tissue engineering scaffolds by reducing cell culture time; which is valuable information for the implant or lab-grown-meat industries.","PeriodicalId":446238,"journal":{"name":"Biotechnology eJournal","volume":"2125 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127469279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Immune-Engineering Biomaterials - a Focus on Galectin Targeting","authors":"S. Martín-Saldaña, M. Chevalier, A. Pandit","doi":"10.2139/ssrn.3793935","DOIUrl":"https://doi.org/10.2139/ssrn.3793935","url":null,"abstract":"The immune system is a complex network that plays a pivotal role in health and is responsible for responding against any challenge that alters the body's homeostasis. Modulating immune response is a widely explored therapeutic strategy for managing the healthy outcome of many diseases. In this sense, discovering new targets in the immune system is of high interest. Among all the biological entities involved in the immune response, galectins, a family of glycan-binding proteins, have been described as key players in immune cell homeostasis and modulation. More importantly, only some members of the galectin family have shown to be crucial in inflammation resolution while others perpetuate the immune response in a pathological context. Being expressed in most major diseases, their potential as targets for new therapies seems promising. Most of the galectin family members' ubiquitous expression points out the need for targeted treatments to secure effectiveness. Engineered biomaterials are emerging as a promising method to improve galectin-targeted strategies' therapeutic performance. In this review, we provide an overview of the role of galectins in health and disease, and their potential as therapeutic targets, as well as the state of the art of galectin-targeted biomaterials.","PeriodicalId":446238,"journal":{"name":"Biotechnology eJournal","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122072528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Designing Biomaterials for the Modulation of Allogeneic and Autoimmune Responses to Cellular Implants in Type 1 Diabetes","authors":"Magdalena M. Samojlik, C. Stabler","doi":"10.2139/ssrn.3784437","DOIUrl":"https://doi.org/10.2139/ssrn.3784437","url":null,"abstract":"The effective suppression of adaptive immune responses is essential for the success of allogeneic cell therapies. In islet transplantation for Type 1 Diabetes, pre-existing autoimmunity provides an additional hurdle, as memory autoimmune T cells mediate both an autoantigen-specific attack on the donor beta cells and an alloantigen-specific attack on the donor graft cells. Immunosuppressive agents used for islet transplantation are generally successful in suppressing alloimmune responses, but dramatically hinder the widespread adoption of this therapeutic approach and fail to control memory T cell populations, which leaves the graft vulnerable to destruction. In this review, we highlight the capacity of biomaterials to provide local and nuanced instruction to suppress or alter immune pathways activated in response to an allogeneic islet transplant. Biomaterial immunoisolation is a common approach employed to block direct antigen recognition and downstream cell-mediated graft destruction; however, immunoisolation alone still permits shed donor antigens to escape into the host environment, resulting in indirect antigen recognition, immune cell activation, and the creation of a toxic graft site. Designing materials to decrease antigen shedding, improve cell viability, and increase material compatibility are all approaches that can decrease antigen shedding and danger signals in the implant microenvironment. Implant materials can be further enhanced through the local delivery of anti-inflammatory, suppressive, chemotactic, and/or tolerogenic agents, which serve to control both the innate and adaptive immune responses to the implant with a benefit of reduced systemic effects. Lessons learned from understanding how to manipulate allogeneic and autogenic immune responses to pancreatic islets can also be applied to other cell therapies to improve their efficacy and duration. Statement of Significance: This review explores key immunologic concepts and critical pathways mediating graft rejection in Type 1 Diabetes, which can instruct the future purposeful design of immunomodulatory biomaterials for cell therapy. A summary of immunological pathways initiated following cellular implantation, as well as current systemic immunomodulatory agents used, is provided. We then outline the potential of biomaterials to modulate these responses. The capacity of polymeric encapsulation to block some powerful rejection pathways is covered. We also highlight the role of cellular health and biocompatibility in mitigating immune responses. Finally, we review the capacity of bioactive materials to proactively modulate local immune responses, focusing on key concepts of anti-inflammatory, suppressive, and tolerogenic agents.","PeriodicalId":446238,"journal":{"name":"Biotechnology eJournal","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114913733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fabrication of Micro-Patterned Calcium Carbonate Materials Through Template-Assisted Microbially Induced Calcium Carbonate Precipitation","authors":"Dewei Yi, Hong Zhang, Wenchao Zhang, Yiwu Zong, Kun Zhao","doi":"10.2139/ssrn.3775869","DOIUrl":"https://doi.org/10.2139/ssrn.3775869","url":null,"abstract":"In this study, we report an approach for fabricating micro-patterned calcium carbonate materials. The approach is based on template-assisted microbially induced calcium carbonate precipitation, and is green and eco-friendly. As a proof of concept, by varying the templates and optimizing fabrication parameters, different patterned calcium carbonate materials were obtained. Materials with periodic patterns were also fabricated through a periodic template, showing a good scalability of this approach. The results of this study have a great potential in various applications, for example, in the fabrication of coating materials and bone-regeneration materials, where patterned calcium carbonate films with controlled morphologies are highly in demand.","PeriodicalId":446238,"journal":{"name":"Biotechnology eJournal","volume":"223 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133373184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multifunctional Ultrasmall AgNP Hydrogel Accelerates Healing of S. Aureus Infected Wounds","authors":"H. Haidari, R. Bright, X. Strudwick, S. Garg, K. Vasilev, A. Cowin, Z. Kopecki","doi":"10.2139/ssrn.3762212","DOIUrl":"https://doi.org/10.2139/ssrn.3762212","url":null,"abstract":"The increasing emergence of antibiotic resistance coupled with the limited effectiveness of current treatments highlights the need for the development of new treatment modalities. Silver nanoparticles (AgNPs) are a promising alternative with broad-spectrum antibacterial activity. However, the clinical translation of AgNPs have been hampered primarily due to the delivery of unsafe levels of silver ions (Ag+) resulting in cellular toxicity and their susceptibility to aggregation resulting in loss of efficacy. Here, we describe a safe and effective, thermo-responsive AgNP hydrogel that provides antibacterial effects in conjunction with wound promoting properties. Using a murine model of wound infection, we demonstrate that the applied AgNP hydrogel to the wound (12 µg silver) not only provides superior bactericidal activity but also reduces inflammation leading to accelerated wound closure when compared to industry-standard silver sulfadiazine (302 µg silver). The AgNP hydrogel-treatment significantly accelerated wound closure at day 4 post-infection (56 closure) compared to both blank hydrogel or Ag SD (74% and 91% closure respectively) with a concurrent increase in PCNA-positive proliferating cells corresponding with a significant 32% improvement in wound re-epithelization compared to the blank hydrogel. Treatment of infected wounds with AgNP hydrogel also decreased neutrophil infiltration, increased anti-inflammatory Ym-1 positive M2 macrophages, and reduced the number of caspase-1 positive apoptotic cells. Therefore, this novel multifunctional AgNP thermo-responsive hydrogel is potentially a safe and effective treatment at much lower concentration for the treatment of wound infections. Statement of Significance: In this study, we describe the development of a multifunctional thermo-responsive hydrogel of ultrasmall silver nanoparticles (AgNPs) for controlled and optimized delivery of silver to infected wounds. The in vivo biological effects of the developed hydrogel showed significant S. aureus elimination from infected mouse wounds compared to a commercial antibacterial formulation. The developed AgNP hydrogel optimally regulates inflammatory responses to promote wound healing as indicated by increased cell proliferation and wound re-epithelization. Additionally, AgNP hydrogel shows significant potential in regulating neutrophil infiltration while increasing levels of anti-inflammatory M2 macrophages and reduces the number of apoptotic cells. Therefore, the multifunctional properties of the developed AgNP thermo-responsive hydrogel offers great clinical potential to control bacterial infections and promote wound healing.","PeriodicalId":446238,"journal":{"name":"Biotechnology eJournal","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116546514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Engineering of Highly Interconnected Inverse Opal Extracellular Matrix Scaffolds for Enhanced Cell Transplantation and Vascularization of Ischemic Tissue","authors":"Wen Li, Ya Bai, Shan Gao, Pan Xu, Guowei Feng, Lichen Wang, Guanwei Fan, Hongjun Wang, Deling Kong, Jun Zhang, Meifeng Zhu","doi":"10.2139/ssrn.3729644","DOIUrl":"https://doi.org/10.2139/ssrn.3729644","url":null,"abstract":"The therapeutic effectiveness of cell transplantation in treatment of diseases and injuries is often limited by low cell retention, survivability, and engraftment. Extracellular matrix (ECM)-derived scaffolds are capable of controlling cell responses, thereby offering potential solutions to current challenges associated with cell therapy. However, it remains a technical challenge to produce ECM scaffolds with highly interconnected porous structure specifically required for cell transplantation. Here, we developed inverse opal porous extracellular matrix (ioECM) scaffolds through subcutaneous implantation of sacrificial templates assembled from polymer microspheres, followed by removal of the microsphere template and cellular content. Such highly interconnected porous ioECM scaffolds supported the anchorage, proliferation, viability, anti-apoptotic and paracrine activities of rat bone marrow mesenchymal stem cells (BMSCs), which further promoted endothelial cell migration, tube formation and proliferation. Upon transplantation into nude mouse critical limb ischemic model, ioECM promoted the engraftment of laden BMSCs, facilitated interconnected vascular network formation with accelerated recovery of blood perfusion and inhibited muscle atrophy and fibrosis. Our study demonstrates a unique strategy to engineer highly porous yet well-interconnected ECM scaffolds specifically for cell transplantation with marked improvement of survivability and vascularization, which offers an essential step toward the success of cell therapy and regenerative medicine.","PeriodicalId":446238,"journal":{"name":"Biotechnology eJournal","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115905985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}