scholarly journals Advantages of Additive Manufacturing for Biomedical Applications of Polyhydroxyalkanoates

2021 ◽  
Vol 8 (2) ◽  
pp. 29
Author(s):  
Alberto Giubilini ◽  
Federica Bondioli ◽  
Massimo Messori ◽  
Gustav Nyström ◽  
Gilberto Siqueira
Keyword(s):  
Additive Manufacturing ◽  
Biomedical Applications ◽  
Growth Conditions ◽  
Special Focus ◽  
Medical Implants ◽  
Production Techniques ◽  
Rapid Prototyping And Manufacturing ◽  
Commercial Applications ◽  
Tunable Mechanical Properties ◽  
Near Future

In recent years, biopolymers have been attracting the attention of researchers and specialists from different fields, including biotechnology, material science, engineering, and medicine. The reason is the possibility of combining sustainability with scientific and technological progress. This is an extremely broad research topic, and a distinction has to be made among different classes and types of biopolymers. Polyhydroxyalkanoate (PHA) is a particular family of polyesters, synthetized by microorganisms under unbalanced growth conditions, making them both bio-based and biodegradable polymers with a thermoplastic behavior. Recently, PHAs were used more intensively in biomedical applications because of their tunable mechanical properties, cytocompatibility, adhesion for cells, and controllable biodegradability. Similarly, the 3D-printing technologies show increasing potential in this particular field of application, due to their advantages in tailor-made design, rapid prototyping, and manufacturing of complex structures. In this review, first, the synthesis and the production of PHAs are described, and different production techniques of medical implants are compared. Then, an overview is given on the most recent and relevant medical applications of PHA for drug delivery, vessel stenting, and tissue engineering. A special focus is reserved for the innovations brought by the introduction of additive manufacturing in this field, as compared to the traditional techniques. All of these advances are expected to have important scientific and commercial applications in the near future.

scholarly journals Bacterial Nanocellulose in Dentistry: Perspectives and Challenges

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 49
Author(s):  
Hélida Gomes de Oliveira Barud ◽  
Robson Rosa da Silva ◽  
Marco Antonio Costa Borges ◽  
Guillermo Raul Castro ◽  
Sidney José Lima Ribeiro ◽  
...  
Keyword(s):  
Tissue Repair ◽  
Biomedical Applications ◽  
Low Cost ◽  
Pulp Tissue ◽  
Bacterial Nanocellulose ◽  
Artificial Blood ◽  
Current Trends ◽  
Artificial Blood Vessels ◽  
Near Future ◽  
Dressing Materials

Bacterial cellulose (BC) is a natural polymer that has fascinating attributes, such as biocompatibility, low cost, and ease of processing, being considered a very interesting biomaterial due to its options for moldability and combination. Thus, BC-based compounds (for example, BC/collagen, BC/gelatin, BC/fibroin, BC/chitosan, etc.) have improved properties and/or functionality, allowing for various biomedical applications, such as artificial blood vessels and microvessels, artificial skin, and wounds dressing among others. Despite the wide applicability in biomedicine and tissue engineering, there is a lack of updated scientific reports on applications related to dentistry, since BC has great potential for this. It has been used mainly in the regeneration of periodontal tissue, surgical dressings, intraoral wounds, and also in the regeneration of pulp tissue. This review describes the properties and advantages of some BC studies focused on dental and oral applications, including the design of implants, scaffolds, and wound-dressing materials, as well as carriers for drug delivery in dentistry. Aligned to the current trends and biotechnology evolutions, BC-based nanocomposites offer a great field to be explored and other novel features can be expected in relation to oral and bone tissue repair in the near future.

Oligonucleotides carrying nucleoside antimetabolites as potential prodrugs

2021 ◽  
Vol 28 ◽  
Author(s):  
Carme Fàbrega ◽  
Anna Clua ◽  
Ramon Eritja ◽  
Anna Aviñó
Keyword(s):  
Antisense Oligonucleotides ◽  
Biomedical Applications ◽  
Enzymatic Degradation ◽  
Research Effort ◽  
Synergetic Effect ◽  
Chemotherapeutic Agents ◽  
Dna Nanostructures ◽  
Chemically Modified ◽  
Near Future ◽  
Large Research

Background: Nucleoside and nucleobase antimetabolites are an important class of chemotherapeutic agents for the treatment of cancer as well as other diseases. Introduction: In order to avoid undesirable side effects, several prodrug strategies have been developed for that purpose. In the present review, we describe a relatively unknown strategy that consists in the use of oligonucleotides modified with nucleoside antimetabolites as prodrugs. Method: The active nucleotides are generated by enzymatic degradation once incorporated into cells. This strategy has attracted large interest and is very active at present due to the continuous developments made on therapeutic oligonucleotides and the recent advances in the field of nanomaterials and nanomedicine. Results: A large research effort was done mainly in the improvement of the antiproliferative properties of nucleoside homopolymers, but recently, chemically modified aptamers, antisense oligonucleotides and/or siRNA carrying antiproliferative nucleotides have demonstrated a great potential due to the synergetic effect of both therapeutic entities. In addition, DNA nanostructures with interesting properties have been built to combine antimetabolites and enhancers of cellular uptake in the same scaffold. Finally, protein nanoparticles functionalized with receptor-binders and antiproliferative oligomers represent a new avenue for a more effective treatment in cancer therapy. Conclusion: It is expected that oligonucleotides carrying nucleoside antimetabolites will be considered as potential drugs in the near future for biomedical applications.

An Assessment on the Benefits of Additive Manufacturing Regarding New Swirler Geometries for Gas Turbine Burners

2018 ◽  
Author(s):  
Fabrice Giuliani ◽  
Nina Paulitsch ◽  
Daniele Cozzi ◽  
Michael Görtler ◽  
Lukas Andracher
Keyword(s):  
Additive Manufacturing ◽  
Gas Turbine ◽  
Inconel 718 ◽  
Advanced Materials ◽  
Gas Turbine Combustor ◽  
Engineering Research ◽  
Know How ◽  
Current State ◽  
Research And Education ◽  
Near Future

In the near future, combustion engineers will shape the burner according to the flame, and not the opposite way anymore. In this contribution, this idea is explored with the help of additive manufacturing (AM). The focus is put on the design and the production of swirlers using advanced materials with the least possible efforts in terms of manufacturing. The material chosen for this study is Inconel 718. There are three motivations to this project. The first one is to design new shapes and assess these in comparison to conventional ones. The second motivation is to be able to manufacture them using additive manufacturing, and to gather know-how on selective laser melting. The third motivation is to elaborate a methodology involving engineering, research and education to promote — only if and when this is desirable — the production of series of premium parts such as high-end components of gas turbine combustor using AM. First-of-a-kind swirler shapes are explained and designed. These are unlikely to be produced using conventional manufacturing. They are then successfully produced in Inconel 718 using AM. The raw parts are directly submitted for testing with no surface post-processing. The paper states why at current state-of-the-art the raw surface quality still needs improvement, and highlights the benefits of the new swirler shape versus conventional.

scholarly journals Chitosan-Based Biocompatible Copolymers for Thermoresponsive Drug Delivery Systems: On the Development of a Standardization System

Pharmaceutics ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1876
Author(s):  
Lorenzo Marsili ◽  
Michele Dal Bo ◽  
Federico Berti ◽  
Giuseppe Toffoli
Keyword(s):  
Drug Delivery ◽  
Biomedical Applications ◽  
Biological Tissues ◽  
Special Focus ◽  
Thermoresponsive Polymers ◽  
Basic Principles ◽  
Natural Polysaccharide ◽  
Non Covalent Interactions ◽  
Covalent Interactions ◽  
Or Applications

Chitosan is a natural polysaccharide that is considered to be biocompatible, biodegradable and non-toxic. The polymer has been used in drug delivery applications for its positive charge, which allows for adhesion with and recognition of biological tissues via non-covalent interactions. In recent times, chitosan has been used for the preparation of graft copolymers with thermoresponsive polymers such as poly-N-vinylcaprolactam (PNVCL) and poly-N-isopropylamide (PNIPAM), allowing the combination of the biodegradability of the natural polymer with the ability to respond to changes in temperature. Due to the growing interest in the utilization of thermoresponsive polymers in the biological context, it is necessary to increase the knowledge of the key principles of thermoresponsivity in order to obtain comparable results between different studies or applications. In the present review, we provide an overview of the basic principles of thermoresponsivity, as well as a description of the main polysaccharides and thermoresponsive materials, with a special focus on chitosan and poly-N-Vinyl caprolactam (PNVCL) and their biomedical applications.

scholarly journals A Review on Development of Bio-Inspired Implants Using 3D Printing

Biomimetics ◽  
2021 ◽  
Vol 6 (4) ◽  
pp. 65
Author(s):  
Ansheed A. Raheem ◽  
Pearlin Hameed ◽  
Ruban Whenish ◽  
Renold S. Elsen ◽  
Aswin G ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Layer By Layer ◽  
Medical Implants ◽  
3D Print ◽  
Metal Implants ◽  
Natural Tissue ◽  
And Control ◽  
Natural Architecture ◽  
Fine Tune

Biomimetics is an emerging field of science that adapts the working principles from nature to fine-tune the engineering design aspects to mimic biological structure and functions. The application mainly focuses on the development of medical implants for hard and soft tissue replacements. Additive manufacturing or 3D printing is an established processing norm with a superior resolution and control over process parameters than conventional methods and has allowed the incessant amalgamation of biomimetics into material manufacturing, thereby improving the adaptation of biomaterials and implants into the human body. The conventional manufacturing practices had design restrictions that prevented mimicking the natural architecture of human tissues into material manufacturing. However, with additive manufacturing, the material construction happens layer-by-layer over multiple axes simultaneously, thus enabling finer control over material placement, thereby overcoming the design challenge that prevented developing complex human architectures. This review substantiates the dexterity of additive manufacturing in utilizing biomimetics to 3D print ceramic, polymer, and metal implants with excellent resemblance to natural tissue. It also cites some clinical references of experimental and commercial approaches employing biomimetic 3D printing of implants.

Recent advancements in lignin valorization and biomedical applications: A patent review

2021 ◽  
Vol 15 ◽  
Author(s):  
Vandana Prasad ◽  
Lubna Siddiqui ◽  
Pawan Kumar Mishra ◽  
Adam Ekielski ◽  
Sushama Talegaonkar
Keyword(s):  
Biomedical Applications ◽  
Drug Carrier ◽  
Industrial Applications ◽  
Future Research ◽  
Lignin Valorization ◽  
New Methods ◽  
Cleaning Agents ◽  
Patent Review ◽  
Commercial Applications ◽  
Made In

Background: Synthetic polymers present disadvantages such as high cost, limited availability, safety concerns, environmental hazards and overtime accumulation in body. Lignin, an aromatic biopolymer, is highly abundant and offers various advantages including cost effectiveness, biocompatibility and biodegradability. It also possesses various pharmacological activities including antioxidant, antibacterial, anticancer and UV protection, thus lignin has become a popular biopolymer in recent years and is no more considered as bio-waste rather an extensive research is been carried out on developing it as drug carrier. Lignin also has non-biomedical applications including dispersing agents, surfactants, detergent/cleaning agents, energy storage, etc. Methods: This review compiles patents granted on production of technical lignin, different lignin therapeutic carriers and its biomedical and non-biomedical applications. The literature is collected from recent years including both articles as well as patents and is carefully analyzed and compiled in an easy to comprehend pattern for guiding future research. Results: The reviewed patents and articles highlighted the advancement made in lignin isolation and valorization. Numerous lignin nanoformulations as drug delivery agents or as standalone entities with various pharmacological actions like antibacterial, antioxidant or UV protectant have been reported. As well as industrial applications of lignin as adhesives, insulators or supercapacitors have also made lignin a biopolymer of choice. Conclusion: Lignin being a bio-inspired polymer has huge potential in commercial applications. New methods of lignin isolation from lignocellulosic biomass including physical pretreatments, solvent fraction, and chemical and biological pretreatment have been widely patented. Several micro/nano lignin formulations with improved and controllable reactivity like nanocontainers, nanocapsules, nanoparticles have also been reported recently. Also various pharmacological properties of lignin have also been explored, thus valorization of lignin is a hot topic of hour.

ADDITIVE MANUFACTURING PARAMETERS OPTIMIZATION OF Ti6AL4V ELI FOR MEDICAL IMPLANTS

2022 ◽  
Author(s):  
VIJAY KUMAR MEENA ◽  
PARVEEN KALRA ◽  
RAVINDRA KUMAR SINHA
Keyword(s):  
Surface Roughness ◽  
Additive Manufacturing ◽  
Weight Ratio ◽  
High Strength ◽  
Surface Characteristics ◽  
Parameters Optimization ◽  
Medical Implants ◽  
Scan Speed ◽  
Grey Relational ◽  
Manufacturing Parameters

Additive manufacturing (AM) of titanium (Ti) alloys has always fascinated researchers owing to its high strength to weight ratio, biocompatibility, and anticorrosive properties, making Ti alloy an ideal candidate for medical applications. The aim of this paper is to optimize the AM parameters, such as Laser Power (LP), Laser Scan Speed (LSS), and Hatch Space (HS), using Analysis of Variance (ANOVA) and Grey Relational analysis (GRA) for mechanical and surface characteristics like hardness, surface roughness, and contact angle, of Ti6Al4V ELI considering medical implant applications. The input parameters are optimized to have optimum hardness, surface roughness and hydrophilicity required for medical implants.

Maximizing design potential: investigating the effects of utilizing opportunistic and restrictive design for additive manufacturing in rapid response solutions

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Rohan Prabhu ◽  
Jordan Scott Masia ◽  
Joseph T. Berthel ◽  
Nicholas Alexander Meisel ◽  
Timothy W. Simpson
Keyword(s):  
Additive Manufacturing ◽  
Design Methodology ◽  
Linear Models ◽  
Design For Additive Manufacturing ◽  
Content Type ◽  
Manufacturing Efficiency ◽  
Material Usage ◽  
Build Time ◽  
Rapid Prototyping And Manufacturing ◽  
Design For Am

Purpose The COVID-19 pandemic has resulted in numerous innovative engineering design solutions, several of which leverage the rapid prototyping and manufacturing capabilities of additive manufacturing. This paper aims to study a subset of these solutions for their utilization of design for AM (DfAM) techniques and investigate the effects of DfAM utilization on the creativity and manufacturing efficiency of these solutions. Design/methodology/approach This study compiled 26 COVID-19-related solutions designed for AM spanning three categories: (1) face shields (N = 6), (2) face masks (N = 12) and (3) hands-free door openers (N = 8). These solutions were assessed for (1) DfAM utilization, (2) manufacturing efficiency and (3) creativity. The relationships between these assessments were then computed using generalized linear models to investigate the influence of DfAM utilization on manufacturing efficiency and creativity. Findings It is observed that (1) unique and original designs scored lower in their AM suitability, (2) solutions with higher complexity scored higher on usefulness and overall creativity and (3) solutions with higher complexity had higher build cost, build time and material usage. These findings highlight the need to account for both opportunistic and restrictive DfAM when evaluating solutions designed for AM. Balancing the two DfAM perspectives can support the development of solutions that are creative and consume fewer build resources. Originality/value DfAM evaluation tools primarily focus on AM limitations to help designers avoid build failures. This paper proposes the need to assess designs for both, their opportunistic and restrictive DfAM utilization to appropriately assess the manufacturing efficiency of designs and to realize the creative potential of adopting AM.

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