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Fulltext Development of power recovery circuit for bio-implantable stimulator

Mokhalad Khaleel Alghrairi, Nasri Bin Sulaiman, Roslina Bt Mohd Sidek, Saad Mutashar

Pertanika Journal of Science & Technology, 2017;25(102):87-96.
MyJurnal

This paper presents a modified design of low power recovery circuit in micro-system implanted device to stimulate the human nerve and muscle. The amplitude shift keying ASK was used to modulate data by using operating frequency 6.78MHz ISM industrial scientific medical band to be less invasive to tissue. The proposed system consists of an external part which has ASK modulator and class-E power amplifier with 94.5% efficiency. The internal part has half wave rectifier and voltage regulator to generate very stable 1.8VDC using 0.35um CMOS technology. The Orcad pspice 16.6 and MULTISIM 11 software were used to simulate the design of power recovery and class-E power amplifier respectively. The regulated voltage utilised to power the sub-electronic device implanted inside human body with very stable voltage even change implanted load resistance. The proposed system has 12.5%modulation index and low power consumption.

Matched MeSH terms: Prostheses and Implants
Bioactivity and mechanical stability of Ti-6Al-4V implants superplastically embedded with hydroxyapatite in rats

Mohd Khalid H, Jauhari I, Mohamad Wali HA, Abdulrazzaq Mahmod S

Biomed Mater, 2017 01 25;12(1):015019.
PMID: 28120816 DOI: 10.1088/1748-605X/aa4f8b

In this in vivo study, Sprague Dawley (SD) rats were used to investigate the bioactivity as well as the microstructural and mechanical properties of Ti-6Al-4V samples embedded with hydroxyapatite (HA) using two different coating methods-superplastic embedment (SPE) and superplastic deformation (SPD). The HA layer thickness for the SPE and SPD samples increased from 249.1 ± 0.6 nm to 874.8 ± 13.7 nm, and from 206.1 ± 5.8 nm to 1162.7 ± 7.9 nm respectively, after 12 weeks of implantation. The SPD sample exhibited much faster growth of newly formed HA compared to SPE. The growth of the newly formed HA was strongly dependent on the degree of HA crystallinity in the initial HA layer. After 12 weeks of implantation, the surface hardness value of the SPE and SPD samples decreased from 661 ± 0.4 HV to 586 ± 1.3 HV and from 585 ± 6.6 HV to 425 ± 86.9 HV respectively. The decrease in surface hardness values was due to the newly formed HA layer that was more porous than the initial HA layer. However, the values were still higher than the substrate surface hardness of 321 ± 28.8 HV. Wear test results suggest that the original HA layers for both samples were still strongly intact, and to a certain extent the newly grown HA layers also were strongly bound with the original HA layers. This study confirms the bioactivity and mechanical stability of the HA layer on both samples in vivo.

Matched MeSH terms: Prostheses and Implants*
Autologous implantation of bilayered tissue-engineered respiratory epithelium for tracheal mucosal regenesis in a sheep model

Mohd Heikal MY, Aminuddin BS, Jeevanan J, Chen HC, Sharifah SH, Ruszymah BH

Cells Tissues Organs (Print), 2010;192(5):292-302.
PMID: 20616535 DOI: 10.1159/000318675

The objective of this study was to regenerate the tracheal epithelium using autologous nasal respiratory epithelial cells in a sheep model. Respiratory epithelium and fibroblast cells were harvested from nasal turbinates and cultured for 1 week. After confluence, respiratory epithelium and fibroblast cells were suspended in autologous fibrin polymerized separately to form a tissue-engineered respiratory epithelial construct (TEREC). A 3 × 2 cm² tracheal mucosal defect was created, and implanted with TEREC and titanium mesh as a temporary scaffold. The control groups were divided into 2 groups: polymerized autologous fibrin devoid of cells (group 1), and no construct implanted (group 2). All sheep were euthanized at 4 weeks of implantation. Gross observation of the trachea showed minimal luminal stenosis formation in the experimental group compared to the control groups. Macroscopic evaluation revealed significant mucosal fibrosis in control group 1 (71.8%) as compared to the experimental group (7%). Hematoxylin and eosin staining revealed the presence of minimal overgrowth of fibrous connective tissue covered by respiratory epithelium. A positive red fluorescence staining of PKH26 on engineered tissue 4 weeks after implantation confirmed the presence of cultured nasal respiratory epithelial cells intercalated with native tracheal epithelial cells. Scanning electron microscopy showed the presence of short microvilli representing immature cilia on the surface of the epithelium. Our study showed that TEREC was a good replacement for a tracheal mucosal defect and was able to promote natural regenesis of the tracheal epithelium with minimal fibrosis. This study highlighted a new technique in the treatment of tracheal stenosis.

Matched MeSH terms: Prostheses and Implants
Polydopamine-assisted chlorhexidine immobilization on medical grade stainless steel 316L: Apatite formation and in vitro osteoblastic evaluation

Mohd Daud N, Hussein Al-Ashwal R, Abdul Kadir MR, Saidin S

Ann. Anat., 2018 Nov;220:29-37.
PMID: 30048761 DOI: 10.1016/j.aanat.2018.06.009

Immobilization of chlorhexidine (CHX) on stainless steel 316L (SS316L), assisted by a polydopamine film as an intermediate layer is projected as an approach in combating infection while aiding bone regeneration for coating development on orthopedic and dental implants. This study aimed to investigate the ability of CHX coating to promote apatite layer, osteoblast cells viability, adhesion, osteogenic differentiation and mineralization. Stainless steel 316L disks were pre-treated, grafted with a polydopamine film and immobilized with different concentrations of CHX (10-30mM). The apatite layer formation was determined through an in vitro simulated body fluid (SBF) test by ATR-FTIR and SEM-EDX analyses. The osteoblastic evaluations including cells viability, cells adhesion, osteogenic differentiation and mineralization were assessed with human fetal osteoblast cells through MTT assay, morphology evaluation under FESEM, ALP enzyme activity and Alizarin Red S assay. The apatite layer was successfully formed on the CHX coated disks, demonstrating potential excellent bioactivity property. The CHX coatings were biocompatible with the osteoblast cells at low CHX concentration (<20mM) with good adhesion on the metal surfaces. The increment of ALP activity and calcium deposition testified that the CHX coated disks able to support osteoblastic maturation and mineralization. These capabilities give a promising value to the CHX coating to be implied in bone regeneration area.

Matched MeSH terms: Prostheses and Implants
Fulltext A Systematic Analysis of Additive Manufacturing Techniques in the Bioengineering of In Vitro Cardiovascular Models

Mohanadas HP, Nair V, Doctor AA, Faudzi AAM, Tucker N, Ismail AF, et al.

Ann Biomed Eng, 2023 Nov;51(11):2365-2383.
PMID: 37466879 DOI: 10.1007/s10439-023-03322-x

Additive Manufacturing is noted for ease of product customization and short production run cost-effectiveness. As our global population approaches 8 billion, additive manufacturing has a future in maintaining and improving average human life expectancy for the same reasons that it has advantaged general manufacturing. In recent years, additive manufacturing has been applied to tissue engineering, regenerative medicine, and drug delivery. Additive Manufacturing combined with tissue engineering and biocompatibility studies offers future opportunities for various complex cardiovascular implants and surgeries. This paper is a comprehensive overview of current technological advancements in additive manufacturing with potential for cardiovascular application. The current limitations and prospects of the technology for cardiovascular applications are explored and evaluated.

Matched MeSH terms: Prostheses and Implants
Ion-Doped Silicate Bioceramic Coating of Ti-Based Implant

Mohammadi H, Sepantafar M

Iran Biomed J, 2016 Sep;20(4):189-200.
PMID: 26979401

Titanium and its alloy are known as important load-bearing biomaterials. The major drawbacks of these metals are fibrous formation and low corrosion rate after implantation. The surface modification of biomedical implants through various methods such as plasma spray improves their osseointegration and clinical lifetime. Different materials have been already used as coatings on biomedical implant, including calcium phosphates and bioglass. However, these materials have been reported to have limited clinical success. The excellent bioactivity of calcium silicate (Ca-Si) has been also regarded as coating material. However, their high degradation rate and low mechanical strength limit their further coating application. Trace element modification of (Ca-Si) bioceramics is a promising method, which improves their mechanical strength and chemical stability. In this review, the potential of trace element-modified silicate coatings on better bone formation of titanium implant is investigated.

Matched MeSH terms: Prostheses and Implants*
Prospects of plasma immersion ion implantation and deposition (PIlI & D) in the biomaterials field in Malaysia and south East Asia

Mohamed MH

Med J Malaysia, 2004 May;59 Suppl B:19-20.
PMID: 15468798

One of the emerging technologies in the area of plasma processing is plasma immersion ion implantation (PSII). The paper addresses the merits offered by the PSII technique especially in the area of biomaterial processing. Worldwide development status as well as the drive towards commercial applications is elaborated in an attempt to draw the attention to the importance of the process for Malaysia as well as south East Asia.

Matched MeSH terms: Prostheses and Implants*
Fulltext Effect of Tricalcium Magnesium Silicate Coating on the Electrochemical and Biological Behavior of Ti-6Al-4V Alloys

Maleki-Ghaleh H, Hafezi M, Hadipour M, Nadernezhad A, Aghaie E, Behnamian Y, et al.

PLoS One, 2015;10(9):e0138454.
PMID: 26383641 DOI: 10.1371/journal.pone.0138454

In the current study, a sol-gel-synthesized tricalcium magnesium silicate powder was coated on Ti-6Al-4V alloys using plasma spray method. Composition of feed powder was evaluated by X-ray diffraction technique before and after the coating process. Scanning electron microscopy and atomic force microscopy were used to study the morphology of coated substrates. The corrosion behaviors of bare and coated Ti-6Al-4V alloys were examined using potentiodynamic polarization test and electrochemical impedance spectroscopy in stimulated body fluids. Moreover, bare and coated Ti-6Al-4V alloys were characterized in vitro by culturing osteoblast and mesenchymal stem cells for several days. Results demonstrated a meaningful improvement in the corrosion resistance of Ti-6Al-4V alloys coated with tricalcium magnesium silicate compared with the bare counterparts, by showing a decrease in corrosion current density from 1.84 μA/cm2 to 0.31 μA/cm2. Furthermore, the coating substantially improved the bioactivity of Ti-6Al-4Valloys. Our study on corrosion behavior and biological response of Ti-6Al-4V alloy coated by tricalcium magnesium silicate proved that the coating has considerably enhanced safety and applicability of Ti-6Al-4V alloys, suggesting its potential use in permanent implants and artificial joints.

Matched MeSH terms: Prostheses and Implants
Double orifice mitral valve: a case report and review of management

Majid AA

J Cardiovasc Surg (Torino), 1991 Nov-Dec;32(6):837-9.
PMID: 1836465

This paper reports a case of double orifice mitral valve which was treated conservatively. A new scheme of classification of this entity linked to the accepted lines of surgical treatment is introduced.

Matched MeSH terms: Prostheses and Implants
Fulltext Electrodeposition of Ginseng/Polyaniline Encapsulated Poly(lactic-co-glycolic Acid) Microcapsule Coating on Stainless Steel 316L at Different Deposition Parameters

Lukman SK, Al-Ashwal RH, Sultana N, Saidin S

Chem Pharm Bull (Tokyo), 2019;67(5):445-451.
PMID: 31061369 DOI: 10.1248/cpb.c18-00847

Electrodeposition is commonly used to deposit ceramic or metal coating on metallic implants. Its utilization in depositing polymer microcapsule coating is currently being explored. However, there is no encapsulation of drug within polymer microcapsules that will enhance its chemical and biological properties. Therefore, in this study, ginseng which is known for its multiple therapeutic effects was encapsulated inside biodegradable poly(lactic-co-glycolic acid) (PLGA) microcapsules to be coated on pre-treated medical grade stainless steel 316L (SS316L) using an electrodeposition technique. Polyaniline (PANI) was incorporated within the microcapsules to drive the formation of microcapsule coating. The electrodeposition was performed at different current densities (1-3 mA) and different deposition times (20-60 s). The chemical composition, morphology and wettability of the microcapsule coatings were characterized through attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM) and contact angle analyses. The changes of electrolyte colors, before and after the electrodeposition were also observed. The addition of PANI has formed low wettability and uniform microcapsule coatings at 2 mA current density and 40 s deposition time. Reduction in the current density or deposition time caused less attachment of microcapsule coatings with high wettability records. While prolonging either one parameter has led to debris formation and melted microcapsules with non-uniform wettability measurements. The color of electrolytes was also changed from milky white to dark yellow when the current density and deposition time increased. The application of tolerable current density and deposition time is crucial to obtain a uniform microcapsule coating, projecting a controlled release of encapsulated drug.

Matched MeSH terms: Prostheses and Implants
Patient-Specific Reconstruction Utilizing Computer Assisted 3D Modelling for Partial Bone Flap Defect in Hybrid Cranioplasty

Low PH, Abdullah JY, Abdullah AM, Yahya S, Idris Z, Mohamad D

J Craniofac Surg, 2019 Jun 28.
PMID: 31261343 DOI: 10.1097/SCS.0000000000005713

PURPOSE: Decompressive craniectomy is a life-saving procedure in the setting of malignant brain swelling. Patients who survive require cranioplasty for anatomical reconstruction and cerebral protection. Autologous cranioplasty remains the commonest practice nowadays, but partial bone flap defects are frequently encountered. The authors, therefore, seek to develop a new technique of reconstruction for cranioplasty candidate with partial bone flap defect utilizing computer-assisted 3D modeling and printing.
METHODS: A prospective study was conducted to evaluate the outcome of a new reconstruction technique that produces patient-specific hybrid polymethyl methacrylate-autologous cranial implant. Computer-assisted 3D modeling and printing was utilized to produce patient-specific molds, which allowed real-time reconstruction of bone flap with partial defect intra-operatively.
RESULTS: Outcome assessment for 11 patients at 6 weeks and 3 months post-operatively revealed satisfactory implant alignment with favorable cosmesis. The mean visual analog scale for cosmesis was 91. Mean implant size was 50cm, and the mean duration of intra-operative reconstruction was 30 minutes. All of them revealed improvement in quality of life following surgery as measured by the SF-36 score. Cost analysis revealed that this technique is more cost-effective compared to customized cranial prosthesis.
CONCLUSION: This new technique and approach produce hybrid autologous-alloplastic bone flap that resulted in satisfactory implant alignment and favorable cosmetic outcome with relatively low costs.

Matched MeSH terms: Prostheses and Implants
The use of freeze-dry bovine pericardium (FDBP) in diaphragmatic herniorrhaphy in dogs

Loqman MY, Wong CM, Hair-Bejo M, Zuki AB, Hafeez YM

Med J Malaysia, 2004 May;59 Suppl B:113-4.
PMID: 15468844

A study was conducted to investigate the effectiveness of freeze-dried bovine pericardium (FDBP) as a biomaterial in diaphragmatic herniorrhapy in dogs. Eight adult dogs were randomly selected and divided into two equal groups. In FDBP group, a diaphragmatic defect was induced and repaired with an identical size of FDBP. In the control group, a diaphragmatic wall was incised at three-side border creating a flap and sutured. Grossly, only mild intrathoracic adhesion was observed for most of the animals, and no herniation occured. Microscopically, the biomaterial incorporated into the host's tissue by ingrowth of young muscle fiber and massive new blood vessel formation in between the fibrous tissue.

Matched MeSH terms: Prostheses and Implants*
Fulltext Vision status: presbyopic patient undergone corneal inlay procedure

Linsay Sundram Gnanasundram, Bashirah Ishak, Aloysius Joseph Low, Rokiah Omar

Jurnal Sains Kesihatan Malaysia, 2016;14(1):1-3.
MyJurnal

This study reports the vision status of a presbyopic patient who has undergone a corneal inlay procedure. The study
hopes to provide optometrists more insight on the procedure and the co-management involved in such a patient. The
patient, a 48 years-old Chinese woman with presbyopia underwent the corneal inlay procedure three years ago.
She had the inlay implanted in the non-dominant eye to aid near vision i.e. her left eye. The pre and post-operative
evaluations include distance and near visual acuity, fundoscopy, tonometry, Schirmer’s test, slit lamp evaluation, corneal
topography and corneal pachymetry. Near visual acuity for the left eye improved from N14 to N5 immediately after
the procedure. Even after 3 years of post-operative followup, the patient was still able to maintain her near vision. In
conclusion, the corneal inlay procedure helped to improve near vision of this presbyopic patient. Optometrist plays
a very important role in the co-management of such patients alongside with the ophthalmologist in terms of visual
functional assessments pre and post-surgery, counseling of the procedure and managing patients’ expectations.

Matched MeSH terms: Prostheses and Implants
Fulltext Amputation in hand surgery

Leung PC

Med J Malaysia, 1986 Sep;41(3):260-3.
PMID: 3312975

When referring to amputation, the immediate association tends to be amputation related to trauma. There is little doubt that injury is by far the commonest cause of amputation, but one must not forget that babies might also be born with amputations of the upper limb. This latter group of amelia composes the various types of congenital amputations.

Matched MeSH terms: Prostheses and Implants
Advancement of Electrospun Nerve Conduit for Peripheral Nerve Regeneration: A Systematic Review (2016-2021)

Lee SY, Thow SY, Abdullah S, Ng MH, Mohamed Haflah NH

Int J Nanomedicine, 2022;17:6723-6758.
PMID: 36600878 DOI: 10.2147/IJN.S362144

Peripheral nerve injury (PNI) is a worldwide problem which hugely affects the quality of patients' life. Nerve conduits are now the alternative for treatment of PNI to mimic the gold standard, autologous nerve graft. In that case, with the advantages of electrospun micro- or nano-fibers nerve conduit, the peripheral nerve growth can be escalated, in a better way. In this systematic review, we focused on 39 preclinical studies of electrospun nerve conduit, which include the in vitro and in vivo evaluation from animal peripheral nerve defect models, to provide an update on the progress of the development of electrospun nerve conduit over the last 5 years (2016-2021). The physical characteristics, biocompatibility, functional and morphological outcomes of nerve conduits from different studies would be compared, to give a better strategy for treatment of PNI.

Matched MeSH terms: Prostheses and Implants*
Microwave-assisted fabrication of titanium implants with controlled surface topography for rapid bone healing

Kutty MG, De A, Bhaduri SB, Yaghoubi A

ACS Appl Mater Interfaces, 2014 Aug 27;6(16):13587-93.
PMID: 25095907 DOI: 10.1021/am502967n

Morphological surface modifications have been reported to enhance the performance of biomedical implants. However, current methods of introducing graded porosity involves postprocessing techniques that lead to formation of microcracks, delamination, loss of fatigue strength, and, overall, poor mechanical properties. To address these issues, we developed a microwave sintering procedure whereby pure titanium powder can be readily densified into implants with graded porosity in a single step. Using this approach, surface topography of implants can be closely controlled to have a distinctive combination of surface area, pore size, and surface roughness. In this study, the effect of various surface topographies on in vitro response of neonatal rat calvarial osteoblast in terms of attachment and proliferation is studied. Certain graded surfaces nearly double the chance of cell viability in early stages (∼one month) and are therefore expected to improve the rate of healing. On the other hand, while the osteoblast morphology significantly differs in each sample at different periods, there is no straightforward correlation between early proliferation and quantitative surface parameters such as average roughness or surface area. This indicates that the nature of cell-surface interactions likely depends on other factors, including spatial parameters.

Matched MeSH terms: Prostheses and Implants*
Fulltext Prevalence of oral tori and exostosis in Malaysian population - A cross-sectional study

Kumar Singh A, Sulugodu Ramachandra S, Arora S, Dicksit DD, Kalyan CG, Singh P

J Oral Biol Craniofac Res, 2017 Sep-Dec;7(3):158-160.
PMID: 29123992 DOI: 10.1016/j.jobcr.2017.08.008

Introduction: Oral tori and exostosis are non-pathological bony protuberances seen on the alveolar surfaces of the jaw bones. These are commonly seen on the palatal surfaces of the maxilla [torus palatinus (TP)] and around the premolars in the lingual surface of the mandible [torus mandibularis (TM)]. The aim of this cross-sectional study was to determine the prevalence of tori/exostosis in the Malaysian population.

Methodology: A total of 2666 patients were examined for the presence of tori and exostosis in the maxilla and mandible and were categorized into TP, TM, and exostosis (facial/labial). Collected data was analysed for obtaining descriptive statistics.

Results: 882 subjects were noticed with oral tori/exostosis among the population studied with a prevalence rate of 33%. TP was seen more in females (35%), compared to males (20%), and this difference was statistically significant (p value

Matched MeSH terms: Prostheses and Implants
Metallic materials stimulating bone formation

Kokubo T

Med J Malaysia, 2004 May;59 Suppl B:91-2.
PMID: 15468833

Metallic materials implanted into bone defects are generally encapsulated by a fibrous tissue. Some metallic materials such as titanium and tantalum, however, have been revealed to bond to the living bone without forming the fibrous tissue, when they were subjected to NaOH solution and heat treatments. Thus treated metals form bone tissue around them even in muscle, when they take a porous form. This kind of osteoconductive and osteoinductive properties are attributed to sodium titanate or tantalate layer on their surfaces formed by the NaOH and heat treatments. These layers induce the deposition of bonelike apatite on the surface of the metals in the living body. This kind of bioactive metals are useful as bone substitutes even highly loaded portions, such as hip joint, spine and tooth root.

Matched MeSH terms: Prostheses and Implants*
Biomaterials research in Malaysia--development in facilities and expertise for in-vivo evaluation

Khalid K

Med J Malaysia, 2004 May;59 Suppl B:133-4.
PMID: 15468854
Matched MeSH terms: Prostheses and Implants*
Chromosome aberration test for hydroxyapatite in sheep

Kannan TP, Nik Ahmad Shah NL, Azlina A, Samsudin AR, Narazah MY, Salleh M

Med J Malaysia, 2004 May;59 Suppl B:168-9.
PMID: 15468871

The present study is aimed at finding the mutagenicity and cytotoxicity of dense form of synthetic hydroxyapatite (Source: School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia) in the blood of sheep. The biomaterial was implanted in the tibia of Malin, an indigenous sheep breed of Malaysia. Blood was collected from the sheep before implantation of the biomaterial, cultured and a karyological study was made. Six weeks after implantation, blood was collected from the same animal, cultured and screened for chromosome aberrations. The mitotic indices and karyological analysis indicated that the implantation of synthetic hydroxyapatite (dense form) did not produce any cytotoxicity or chromosome aberrations in the blood of sheep.

Matched MeSH terms: Prostheses and Implants*

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