A state-of-the-art review on recent advances in the fabrication and characteristics of magnesium-based alloys in biomedical applications

Magnesium(Mg)and its alloys have recently gained increasing attention in the biomedical field as promising biodegradable materials with harmless degradation products.Magnesium-based alloys have a wide range of biomedical applications because of their outstanding biocompatibility and unique mechanical properties.Widespread use of Mg-based biomedical devices eliminates the need for post-healing biomaterial removal surgery and minimizes the negative consequences of the implantation of permanent biomaterials,including stress shielding and undesired metal ion release in the body.This paper provides a literature review on the properties and manufacturing methods of Mgbased alloys for biomedical applications,including orthopedic implants,cardiovascular applications,surgical wires and staplers,and antitumor activities.Each application of Mg-based biomaterials is investigated from a biological perspective,including matching functional properties,biocompatibility,host tissue responses,and anti-microbial strategies,along with potential additive manufacturing technologies for these applications.Finally,an outlook is presented to provide recommendations for Mg-based biomaterials in the future.

A state-of-the-art review of the fabrication and characteristics of titanium and its alloys for biomedical applications

Commercially pure titanium and titanium alloys have been among the most commonly used materials for biomedical applications since the 1950 s.Due to the excellent mechanical tribological properties,corrosion resistance,biocompatibility,and antibacterial properties of titanium,it is getting much attention as a biomaterial for implants.Furthermore,titanium promotes osseointegration without any additional adhesives by physically bonding with the living bone at the implant site.These properties are crucial for producing high-strength metallic alloys for biomedical applications.Titanium alloys are manufactured into the three types ofα,β,andα+β.The scientific and clinical understanding of titanium and its potential applications,especially in the biomedical field,are still in the early stages.This review aims to establish a credible platform for the current and future roles of titanium in biomedicine.We first explore the developmental history of titanium.Then,we review the recent advancement of the utility of titanium in diverse biomedical areas,its functional properties,mechanisms of biocompatibility,host tissue responses,and various relevant antimicrobial strategies.Future research will be directed toward advanced manufacturing technologies,such as powder-based additive manufacturing,electron beam melting and laser melting deposition,as well as analyzing the effects of alloying elements on the biocompatibility,corrosion resistance,and mechanical properties of titanium.Moreover,the role of titania nanotubes in regenerative medicine and nanomedicine applications,such as localized drug delivery system,immunomodulatory agents,antibacterial agents,and hemocompatibility,is investigated,and the paper concludes with the future outlook of titanium alloys as biomaterials.

The journey of multifunctional bone scaffolds fabricated from traditional toward modern techniques

As a bone scaffold,meeting all basic requirements besides dealing with other bone-related issues-bone cancer and accelerated regeneration-is not expected from traditional scaffolds,but a newer class of scaffolds called multifunctional.From a clinical point of view,being a multifunctional scaffold means reducing in healing time,direct costs-medicine,surgery,and hospitalization-and indirect costs-loss of mobility,losing job,and pain.The main aim of the present review is following the multifunctional bone scaffolds trend to deal with both bone regeneration and cancer therapy.Special consideration is given to different fabrication techniques which have been applied to yield these materials spanning from traditional to modern ones.Moreover,the hierarchical structure of bone plus bone cancers and available medicines to them are introduced to familiarize the potential reader of review with the pluri-disciplinary essence of the field.Eventually,a brief discussion relating to the future trend of these materials is provided.

Electrospun Aligned PCL/Gelatin Scaffolds Mimicking the Skin ECM for Effective Antimicrobial Wound Dressings

Bacterial infections and multidrug-resistant bacteria are major health burdens in wound care.Biocompatible antimicrobial agents,e.g.,ε-polylysine(ε-PL),provide a broad spectrum of antibacterial properties and support dermal cell growth.Here,ε-PL was incorporated into polycaprolactone(PCL)/gelatin electrospun scaffolds collected at varying rotation speeds.Then,the samples were crosslinked using dopamine hydrochloride to provide highly proliferative dressings with broad antimicrobial activity.The morphological study showed that the electrospun wound dressings were smooth,continuous,and bead-free,with a mean diameter ranging from 267±7 to 331±8 nm for all random and aligned nanofibers.The fiber alignment of the electrospun PCL/gelatin scaffolds improved their tensile strength and modulus.Moreover,nanofiber mats are highly hydro-philic,which is crucial for an efficient wound dressing.The samples also demonstrated high antimicrobial properties against common wound bacterial strains,including methicillin-resistant Staphylococcus aureus(MRSA),Staphylococcus aureus(SA),Escherichia coli(EC),Acinetobacter baumannii(AB),and Pseudomonas aeruginosa(PA).Mammalian cell prolifera-tion and morphology assays involving primary human dermal fibroblasts(hDFs)and immortalized keratinocytes(HaCaT)showed excellent biocompatibility of the electrospun mats and remarkably aligned mats.Furthermore,aligned mats showed more cell migration than randomly oriented mats,which is desirable for more efficient wound healing.Therefore,it can be concluded that aligned PCL/gelatin mats containingε-PL are promising for potential use in wound dressings.