Applied Sciences

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3 pages, 159 KiB

Open AccessEditorial

Editorial Introduction to the Special Issue “Biomaterials and Biofabrication”

by Jangho Kim, Kyunghoon Kim and Hong Nam Kim

Appl. Sci. 2020, 10(18), 6388; https://doi.org/10.3390/app10186388 - 14 Sep 2020

Viewed by 1781

Abstract

This Special Issue “Biomaterials and Biofabrication” of applied sciences comprises 10 papers that are the latest advances in basic and application research in the field of biomaterials and biofabrication [...] Full article

(This article belongs to the Special Issue Biomaterials and Biofabrication)

Research

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10 pages, 2235 KiB

Open AccessCommunication

Graphene–Chitosan Hybrid Dental Implants with Enhanced Antibacterial and Cell-Proliferation Properties

by Sunho Park, Hyeran Kim, Kyoung Soon Choi, Min-Kyung Ji, Sujin Kim, Yonghyun Gwon, Chan Park, Jangho Kim and Hyun-Pil Lim

Appl. Sci. 2020, 10(14), 4888; https://doi.org/10.3390/app10144888 - 16 Jul 2020

Cited by 19 | Viewed by 3002

Abstract

Dental implants are widely used tooth replacement tools owing to their good oral rehabilitation and reconstruction capacities. Since dental implants are designed as a replacement for natural teeth, multi-functional abilities are desired to achieve successful implant treatment with improved osseointegration through promotion of [...] Read more.

Dental implants are widely used tooth replacement tools owing to their good oral rehabilitation and reconstruction capacities. Since dental implants are designed as a replacement for natural teeth, multi-functional abilities are desired to achieve successful implant treatment with improved osseointegration through promotion of mammalian cell activity and prevention of bacterial cell activity. In this study, we developed a graphene–chitosan hybrid dental implant (GC hybrid implant) using various concentrations of graphene, which demonstrated the different surface properties including increased wettability and roughness. Importantly, the GC hybrid implant under the optimal condition (i.e., 1% GC hybrid implant) could significantly promote osteoblast proliferation while reducing biofilm formation and bacterial activity. Our study demonstrates the potential of using this GC hybrid implant as a new type of dental implant, which can offer an effective design for the fabrication of advanced dental implants. Full article

(This article belongs to the Special Issue Biomaterials and Biofabrication)

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10 pages, 1872 KiB

Open AccessCommunication

Cell-Laden Thermosensitive Chitosan Hydrogel Bioinks for 3D Bioprinting Applications

by Jongbeom Ku, Hoon Seonwoo, Sangbae Park, Kyoung-Je Jang, Juo Lee, Myungchul Lee, Jae Woon Lim, Jangho Kim and Jong Hoon Chung

Appl. Sci. 2020, 10(7), 2455; https://doi.org/10.3390/app10072455 - 03 Apr 2020

Cited by 34 | Viewed by 4641

Abstract

Three-dimensional (3D) bioprinting is a technology used to deposit cell-laden biomaterials for the construction of complex tissues. Thermosensitive hydrogels are physically cross-linked by non-covalent interaction without using crosslinkers, facilitating low cytotoxicity and cell viability. Chitosan, which is a non-toxic, biocompatible and biodegradable polysaccharide, [...] Read more.

Three-dimensional (3D) bioprinting is a technology used to deposit cell-laden biomaterials for the construction of complex tissues. Thermosensitive hydrogels are physically cross-linked by non-covalent interaction without using crosslinkers, facilitating low cytotoxicity and cell viability. Chitosan, which is a non-toxic, biocompatible and biodegradable polysaccharide, can be used as a thermosensitive hydrogel. Therefore, chitosan hydrogel could be of potential use as a 3D bioprinting ink. The purpose of this study was to develop and compare the effectivity of different bioinks based on chitosan hydrogels for 3D bioprinting. The solvent type did not affect the gel shape and gelation time, whereas acetic acid exhibited better biocompatibility compared to lactic and hydrochloric acids. The nature of the gelling agent was found to have a stronger influence on these characteristics than that of the solvent. The NaHCO₃ moiety exhibited a higher growth rate of the storage modulus (G′) and a more irregular porous structure than that of the β-glycerophosphate (β-GP) and K₂HPO₄ groups. Cell viability, and live and dead assays, showed that the NaHCO₃ group was more efficient for cell adhesion. The type of gelling agent did not lead to appreciable differences in cell-laden constructs. The NaHCO₃ group was more amenable to bioprinting, compared to the β-GP and K₂HPO₄ groups. The chitosan hydrogel bioinks could, therefore, be good candidates for 3D bioprinting and would pave the way for patient-specific regenerative medicines. Full article

(This article belongs to the Special Issue Biomaterials and Biofabrication)

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14 pages, 2983 KiB

Open AccessArticle

Lithographically-Fabricated HA-Incorporated PCL Nanopatterned Patch for Tissue Engineering

by Kyoung-Je Jang, Sujin Kim, Sangbae Park, Woochan Kim, Yonghyun Gwon, Sunho Park, Ki-Taek Lim, Hoon Seonwoo and Jangho Kim

Appl. Sci. 2020, 10(7), 2398; https://doi.org/10.3390/app10072398 - 01 Apr 2020

Cited by 9 | Viewed by 2899

Abstract

Inspired by the aligned extracellular matrix and bioceramics in human bone tissue, we investigated the relative contributions of nanotopography and equine bone powders (EBPs) with human dental pulp stem cells (DPSCs) to the osteogenesis. Both nanotopography and EBPs independently promoted the osteogenesis of [...] Read more.

Inspired by the aligned extracellular matrix and bioceramics in human bone tissue, we investigated the relative contributions of nanotopography and equine bone powders (EBPs) with human dental pulp stem cells (DPSCs) to the osteogenesis. Both nanotopography and EBPs independently promoted the osteogenesis of DPSCs, osteogenesis was further promoted by the two factors in combination, indicating the importance of synergistic design factor of guided bone regeneration (GBR) membrane. The osteogenesis of DPSCs was affected by the polycaprolactone-based nanotopography of parallel nanogrooves as well as EBPs coating. Interestingly, both nanopattern and EBPs affected the DPSCs morphologies; nanopattern led to cell elongation and EBPs led to cell spreading and clustering. Analysis of the DPSCs-substrate interaction, DPSCs-EBPs interaction suggests that the combined environment of both factors play a crucial role in mediating osteogenic phenotype. This simple method to achieve a suitable environment for osteogenesis via nanotopography and EBPs coating modulation may be regarded as a promising technique for GBR/GTR membranes, which widely used dental and maxillofacial surgery applications. Full article

(This article belongs to the Special Issue Biomaterials and Biofabrication)

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14 pages, 5485 KiB

Open AccessArticle

Pneumatically Actuated Microfluidic Platform for Reconstituting 3D Vascular Tissue Compression

by Jungho Ahn, Hyeok Lee, Habin Kang, Hyeri Choi, Kyungmin Son, James Yu, Jungseub Lee, Jungeun Lim, Dohyun Park, Maenghyo Cho and Noo Li Jeon

Appl. Sci. 2020, 10(6), 2027; https://doi.org/10.3390/app10062027 - 17 Mar 2020

Cited by 12 | Viewed by 3685

Abstract

In vivo, blood vessels constitutively experience mechanical stresses exerted by adjacent tissues and other structural elements. Vascular collapse, a structural failure of vascular tissues, may stem from any number of possible compressive forces ranging from injury to tumor growth and can promote inflammation. [...] Read more.

In vivo, blood vessels constitutively experience mechanical stresses exerted by adjacent tissues and other structural elements. Vascular collapse, a structural failure of vascular tissues, may stem from any number of possible compressive forces ranging from injury to tumor growth and can promote inflammation. In particular, endothelial cells are continuously exposed to varying mechanical stimuli, internally and externally, resulting in blood vessel deformation and injury. This study proposed a method to model biomechanical-stimuli-induced blood vessel compression in vitro within a polydimethylsiloxane (PDMS) microfluidic 3D microvascular tissue culture platform with an integrated pneumatically actuated compression mechanism. 3D microvascular tissues were cultured within the device. Histological reactions to compressive forces were quantified and shown to be the following: live/dead assays indicated the presence of a microvascular dead zone within high-stress regions and reactive oxygen species (ROS) quantification exhibited a stress-dependent increase. Fluorescein isothiocyanate (FITC)-dextran flow assays showed that compressed vessels developed structural failures and increased leakiness; finite element analysis (FEA) corroborated the experimental data, indicating that the suggested model of vascular tissue deformation and stress distribution was conceptually sound. As such, this study provides a powerful and accessible in vitro method of modeling microphysiological reactions of microvascular tissues to compressive stress, paving the way for further studies into vascular failure as a result of external stress. Full article

(This article belongs to the Special Issue Biomaterials and Biofabrication)

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14 pages, 5145 KiB

Open AccessArticle

Preparation and Characterization for Antibacterial Activities of 3D Printing Polyetheretherketone Disks Coated with Various Ratios of Ampicillin and Vancomycin Salts

by Ngi-Chiong Lau, Min-Hua Tsai, Dave W. Chen, Chien-Hao Chen and Kong-Wei Cheng

Appl. Sci. 2020, 10(1), 97; https://doi.org/10.3390/app10010097 - 20 Dec 2019

Cited by 11 | Viewed by 2652

Abstract

In this study, polyetheretherketone (PEEK) materials coated with various ratios of two kinds of antibiotic agents (ampicillin and/or vancomycin salts) were prepared. A modified 3D printer based on fused deposition modeling was employed to prepare PEEK disks. Coating ampicillin and/or vancomycin salts onto [...] Read more.

In this study, polyetheretherketone (PEEK) materials coated with various ratios of two kinds of antibiotic agents (ampicillin and/or vancomycin salts) were prepared. A modified 3D printer based on fused deposition modeling was employed to prepare PEEK disks. Coating ampicillin and/or vancomycin salts onto the PEEK disks was carried out using the biodegradable poly (lactic-co-glycolic acid) (PLGA) polymer as a binder and a control unit for the drug release in the buffer solution. The effects of various rations of ampicillin and/or vancomycin salts in the PLGA polymer on the PEEK substrates, the release profiles of various drugs, and antibacterial activities of the samples were investigated. Temperature of the heated nozzle in a commerical 3D printer was set at 340 °C. After systemic investigations of the qualities of PEEK disks, a diameter of the heated nozzle of 0.6 mm in the 3D printer was employed for the preparation of PEEK disks. Results of drug release profiles from samples into buffer solution show that the antibacterial activities of samples can continue up to 28 days. In the inhibition zone test of samples, the release amounts of antibiotic agents from the PEEK samples can inhibit S. aureus with activity of over 40% in 30 days tests and most of them can have inhibition activities of higher than 60% during the test. These results showed that a simple and low-cost 3D printing method for the preparation of PEEK/antibiotic agents/PLGA samples can have further applications in biomedical-related technology. Full article

(This article belongs to the Special Issue Biomaterials and Biofabrication)

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8 pages, 1698 KiB

Open AccessCommunication

Effects of an Acetic Acid and Acetone Mixture on the Characteristics and Scaffold–Cell Interaction of Electrospun Polycaprolactone Membranes

by Minh Hieu Ho, Thien Bui-Thuan Do, Nhi Ngoc-Thao Dang, An Nguyen-My Le, Hanh Thi-Kieu Ta, Toi Van Vo and Hiep Thi Nguyen

Appl. Sci. 2019, 9(20), 4350; https://doi.org/10.3390/app9204350 - 16 Oct 2019

Cited by 17 | Viewed by 5295

Abstract

Green electrospinning has attracted great interest since non-toxic solvents were shown to be applicable in the fabrication of fibrous materials while ensuring health safety and environmental protection. Less harmful reagents such as acetone (AC) and acetic acid (AA) have been employed in this [...] Read more.

Green electrospinning has attracted great interest since non-toxic solvents were shown to be applicable in the fabrication of fibrous materials while ensuring health safety and environmental protection. Less harmful reagents such as acetone (AC) and acetic acid (AA) have been employed in this field in recent years. However, research in this area is still rare, yielding only preliminary results. In this study, two different types of solvents (pure AC and an AA/AC mixture) were used to fabricate electrospun polycaprolactone (PCL) membranes. Sample morphology, wettability, tensile strength, and chemical composition were compared between two types of membranes. Cell–scaffold interaction was also examined by cell adhesion and proliferation assays. The results demonstrate that the two types of solvents had significant effects on membrane morphology, physical strength, and cell adherence behaviors, which should be considered for different application purposes. Full article

(This article belongs to the Special Issue Biomaterials and Biofabrication)

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11 pages, 2886 KiB

Open AccessArticle

Comparison of the Pullout Strength of Pedicle Screws According to the Thread Design for Various Degrees of Bone Quality

by Feng Shen, Ho-Joong Kim, Kyoung-Tak Kang and Jin S. Yeom

Appl. Sci. 2019, 9(8), 1525; https://doi.org/10.3390/app9081525 - 12 Apr 2019

Cited by 11 | Viewed by 6810

Abstract

Although dual-threaded pedicle screws have been developed, the advantages over single-threaded screws remain controversial. We aimed to investigate the biomechanical performance of two types of dual-threaded pedicle screw by comparing their pullout strength with that of a single-threaded screw in relation to bone [...] Read more.

Although dual-threaded pedicle screws have been developed, the advantages over single-threaded screws remain controversial. We aimed to investigate the biomechanical performance of two types of dual-threaded pedicle screw by comparing their pullout strength with that of a single-threaded screw in relation to bone quality. Four types of pedicle screw with different thread patterns were designed. Type I: single-threaded screw; Type II: double-threaded screw; Type III: dual-threaded screw; Type IV: a newly designed double dual-threaded screw. Five types of polyurethane foams simulating various degrees of bone quality were used. These were: Type A: cancellous bone; Type B: cancellous bone with cortical bone in the upper margin; Type C: osteoporotic cancellous bone; Type D: osteoporotic cancellous bone with cortical bone in the upper margin; and Type E: osteoporotic bone with cortical bone in the upper and lower margins. A comparison of the pullout strength of Type I, II, and III screws in Type A, B, C and D bone specimens was performed. Type C and E bone specimens were used for comparisons among Type I, II, and IV screws. Compared to the single-threaded screw, the dual-threaded pedicle screws exhibited higher pullout strength in normal-quality bone and significantly lower pullout strength in compromised osteoporotic bone. However, the double dual-threaded screw exhibited better pullout biomechanics in osteoporotic bone with bi-cortical bone. Full article

(This article belongs to the Special Issue Biomaterials and Biofabrication)

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Review

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25 pages, 1643 KiB

Open AccessReview

Retinal Drug Delivery: Rethinking Outcomes for the Efficient Replication of Retinal Behavior

by Eliana B. Souto, Elena Sanchez-Lopez, Joana R. Campos, Raquel da Ana, Marta Espina, Maria L. Garcia, Patrícia Severino, Fernando Batain, Thais F. R. Alves, Kessi M. M. Crescencio, Selma B. Souto and Marco V. Chaud

Appl. Sci. 2020, 10(12), 4258; https://doi.org/10.3390/app10124258 - 21 Jun 2020

Cited by 4 | Viewed by 2743

Abstract

The retina is a highly organized structure that is considered to be "an approachable part of the brain." It is attracting the interest of development scientists, as it provides a model neurovascular system. Over the last few years, we have been witnessing significant [...] Read more.

The retina is a highly organized structure that is considered to be "an approachable part of the brain." It is attracting the interest of development scientists, as it provides a model neurovascular system. Over the last few years, we have been witnessing significant development in the knowledge of the mechanisms that induce the shape of the retinal vascular system, as well as knowledge of disease processes that lead to retina degeneration. Knowledge and understanding of how our vision works are crucial to creating a hardware-adaptive computational model that can replicate retinal behavior. The neuronal system is nonlinear and very intricate. It is thus instrumental to have a clear view of the neurophysiological and neuroanatomic processes and to take into account the underlying principles that govern the process of hardware transformation to produce an appropriate model that can be mapped to a physical device. The mechanistic and integrated computational models have enormous potential toward helping to understand disease mechanisms and to explain the associations identified in large model-free data sets. The approach used is modulated and based on different models of drug administration, including the geometry of the eye. This work aimed to review the recently used mathematical models to map a directed retinal network. Full article

(This article belongs to the Special Issue Biomaterials and Biofabrication)

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17 pages, 1887 KiB

Open AccessReview

Vascularized Lower Respiratory-Physiology-On-A-Chip

by Hyoryung Nam, Yoo-mi Choi and Jinah Jang

Appl. Sci. 2020, 10(3), 900; https://doi.org/10.3390/app10030900 - 30 Jan 2020

Cited by 12 | Viewed by 4827

Abstract

Recently, respiratory systems are increasingly threatened by high levels of environmental pollution. Organ-on-a-chip technology has the advantage of enabling more accurate preclinical experiments by reproducing in vivo organ physiology. To investigate disease mechanisms and treatment options, respiratory-physiology-on-a-chip systems have been studied for the [...] Read more.

Recently, respiratory systems are increasingly threatened by high levels of environmental pollution. Organ-on-a-chip technology has the advantage of enabling more accurate preclinical experiments by reproducing in vivo organ physiology. To investigate disease mechanisms and treatment options, respiratory-physiology-on-a-chip systems have been studied for the last decade. Here, we delineate the strategic approaches to develop respiratory-physiology-on-a-chip that can recapitulate respiratory system in vitro. The state-of-the-art biofabrication methods and biomaterials are considered as key contributions to constructing the chips. We also explore the vascularization strategies to investigate complicated pathophysiological phenomena including inflammation and immune responses, which are the critical aggravating factors causing the complications in the respiratory diseases. In addition, challenges and future research directions are delineated to improve the mimicry of respiratory systems in terms of both structural and biological behaviors. Full article

(This article belongs to the Special Issue Biomaterials and Biofabrication)

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11 pages, 1237 KiB

Open AccessReview

Toward Long-Term Implantable Glucose Biosensors for Clinical Use

by Yun Jung Heo and Seong-Hyok Kim

Appl. Sci. 2019, 9(10), 2158; https://doi.org/10.3390/app9102158 - 27 May 2019

Cited by 19 | Viewed by 7013

Abstract

Continuous glucose monitoring (CGM) sensors have led a paradigm shift to painless, continuous, zero-finger pricking measurement in blood glucose monitoring. Recent electrochemical CGM sensors have reached two-week lifespans and no calibration with clinically acceptable accuracy. The system with the recent CGM sensors is [...] Read more.

Continuous glucose monitoring (CGM) sensors have led a paradigm shift to painless, continuous, zero-finger pricking measurement in blood glucose monitoring. Recent electrochemical CGM sensors have reached two-week lifespans and no calibration with clinically acceptable accuracy. The system with the recent CGM sensors is identified as an “integrated glucose monitoring system,” which can replace finger-pricking glucose-testing for diabetes treatment decisions. Although such innovation has brought CGM technology closer to realizing the artificial pancreas, discomfort and infection problems have arisen from short lifespans and open wounds. A fully implantable sensor with a longer-term lifespan (90 days) is considered as an alternative CGM sensor with high comfort and low running cost. However, it still has barriers, including surgery for applying and replacing and frequent calibration. If technical refinement is conducted (e.g., stability and reproducibility of sensor fabrication), fully implantable, long-term CGM sensors can open the new era of continuous glucose monitoring. Full article

(This article belongs to the Special Issue Biomaterials and Biofabrication)

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