Conductive scaffolds with tailored surface properties are critical for neural tissue engineering. Here, we report surface-engineered polyaniline (PANI) nanofibers doped with taurine (Tau), a bioactive amino acid, to simultaneously enhance electrical conductivity (0.018 S/cm), antioxidant activity (41.3 % radical scavenging), and neural differentiation. Unlike conventional dopants (e.g., camphor sulfonic acid), Tau eliminates cytotoxicity while promoting stem cell proliferation and upregulating neural markers (Map2, Nurr1). Through electrospinning and in-situ polymerization, we fabricated two scaffold architectures: blended PANI-Tau/PES (BPPT) and PANI-Tau-coated PES (CPPT). CPPT exhibited superior surface hydrophilicity (contact angle: 72 degrees vs. 127 degrees for BPPT) and porosity (73 % vs. 59 % for BPPT). The results showed that using Tau as the dopant and the preparation method of nanofibers (blending or coating) changed the morphology, chemical properties, hydrophilicity/hydrophobicity, porosity, antioxidant activity, and conductivity of the scaffolds. Electrical stimulation (15 Hz, 100 mV) further amplified neural differentiation in Tau-doped scaffolds, demonstrating synergistic effects of surface chemistry and electroactivity. This work provides a strategy to engineer conductive biomaterials with multifunctional surfaces for neural regeneration.

BACKGROUND:Bone morphogenetic protein (BMP) signaling is crucial for osteogenic (OS) differentiation, bone growth, and repair. However, the clinical use of BMPs is limited due to their cost and challenges in delivery. SB4, a potent compound of benzoxazole, is a newly introduced small molecule shown to activate the BMP signaling pathway. In this study, we investigated the effects of SB4 on OS differentiation of adipose-derived mesenchymal stem cells (ADMSCs). METHODS:We first examined whether BMP signaling is active in osteoinduced ADMSCs. ADMSCs were treated with SB4 (5 and 10 μM) for 24 hr, and mRNA expression of BMP direct target genes (ID1 and ID3) was analyzed. ADMSCs were then cultured with or without SB4 (10 μM) for 7, 14, and 21 days, followed by Alizarin red staining and real-time polymerase chain reaction analysis of mRNA expression of OS markers RUNX2, BMP2, alkaline phosphatase (ALP), and Osteopontin. To investigate the most effective time period of SB4 in osteogenesis, SB4 was applied every 3.5 days during the 21-day differentiation period. RESULTS:After 24 hr of treatment with SB4 (5 and 10 μM), increased mRNA expression of BMP direct target genes (ID1 and ID3) confirmed that SB4 acts as an active BMP agonist. SB4-treated ADMSCs showed enhanced bone matrix production and increased mRNA expression of RUNX2, BMP2, ALP, and Osteopontin. Increased mRNA expression of OS markers, bone matrix formation, and ALP activity during the first 7 days of SB4 treatment suggested the importance of SB4 at the early stage of differentiation. CONCLUSIONS:These results indicate that SB4, with potential BMP-like activity, induces OS differentiation of ADMSCs, leading it to serve as a cost-effective BMP agonist for osteogenesis-related research as well as a potential therapeutic agent for bone repair and regeneration.

Polyesters and thermoplastic polyurethanes (TPUs) based on polyesters, as biodegradable and eco-friendly synthetic polymers, were the focus of research in recent years with promising for results for tissue engineering (TE) applications. Among the commercially available polyesters, the potential of the semi-crystalline poly (butylene succinate) (PBS) as polyols was not explored in depth. In this regard, we synthesized a PBS-diol oligomer through esterification between butylene glycol and succinic acid; the oligomer was characterized using NMR analysis. It was subsequently used as polyol for the catalyst- free synthesis of TPUs using hexamethylene diisocyanate (HDI). The FTIR results revealed successful completion of prepolymerization reaction after 2 h in the absence of toxic tin- based catalyst. The TPUs possessed high elastic modulus ( E ) due to high PBS crystallinity. Incorporating CeO2 nanoparticles, as an antioxidant, into the TPU with HDI: PBS-diol molar ratio of 4:1 resulted in an unprecedented rise in E from 49.0 to 186.5 MPa once 0.25 wt

Heparin holds promise for cardiac tissue engineering, but challenges such as hematoma or bleeding and accumulation in tissue caused by excessive release, and short half-life persist. The present study aimed to introduce a reliable mechanism for the prolonged heparin release from a biocompatible polymer carrier. The designed system must ensure that heparin retains its bioactivity over time while preventing premature release. Heparin was encapsulated within poly (L-lactic acid) microparticles using the double emulsion method, with polyvinyl alcohol employed as the stabilizer. The encapsulation efficiency of heparin in the microparticles was calculated as 25.56 %. The functionality of the design was evaluated using Attenuated Total Reflection Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, and Energy Dispersive X-ray Spectroscopy. Drug release and microparticle degradation studies were conducted alongside cell viability tests. The particle sizes ranged from 5 to 10 +/- 2.53 mu m, with evidence suggesting that heparin promotes the smaller particle formation. The system demonstrated a consistent drug release profile over six weeks with a release rate of 54 % by week two and 97.65 % by week six. The degradation of heparin-loaded microparticles reached less than 50 % by week six, and the loading of heparin did not significantly affect the degradation behavior of the PLLA microparticles in PBS. Furthermore, heparin concentrations between 200 and 400 mu g/ml enhanced the viability of Placenta-derived Mesenchymal Stem Cells and H9c2. These findings suggest that the system could be considered as an effective vehicle for sustained heparin delivery across a spectrum of biological applications, particularly in cardiac tissue engineering.

Amniotic membrane (AM) is an attractive source for bone tissue engineering because of its low immunogenicity, contains biomolecules and proteins, and osteogenic differentiation properties. Hydroxyapatite is widely used as bone scaffolds due to its biocompatibility and bioactivity properties. The aim of this study is to design and fabricate scaffold based on hydroxyapatite-coated decellularized amniotic membrane (DAM-HA) for bone tissue engineering purpose. So human amniotic membranes were collected from healthy donors and decellularized (DAM). Then a hydroxyapatite-coating was created by immersion in 10X SBF, under variable parameters of pH and incubation time. Hydroxyapatite-coating was characterized and the optimal sample was selected. Human adipose-derived mesenchymal stem cell behaviors were assessed on control, amniotic membrane, and coated amniotic membrane. The results of the SEM, MTT assay, and Live-Dead staining showed that DAM and DAM-HA support cell adhesion, viability and proliferation. Osteogenic differentiation was evaluated by assessment of alkaline phosphatase activity and expression of osteogenic markers. Maximum gene expression values compared to control occurred in 14 days for alkalin phosphatase, while the highest values for osteocalcin and osteopontin in 21 days. These gene expression values in DAM and DAM-HA for alkalin phosphatase is 6.41 and 8.47, for osteocalcin is 3.95 and 5.94 and for osteopontin is 5.59 and 9.9 respectively. The results of this study indicated DAM supports the survival and growth of stem cells. Also, addition of hydroxyapatite component to DAM promotes osteogenic differentiation while maintaining viability. Therefore, hydroxyapatite-coated decellularized amniotic membrane can be a promising choice for bone tissue engineering applications.

Insufficient levels of nitric oxide may lead to chronic and acute wounds. Additionally, it is crucial that nitric oxide is prepared in a controlled-release manner due to its gaseous nature and short half-life. To address this issue, utilizing nitric oxide donors, particularly S-nitrosothiols such as S-nitrosoglutathione (GSNO), could efficiently overcome instability and aid in biomedical applications. Decellularized human amniotic membranes are also best known for their anti-inflammatory, angiogenic, and antimicrobial properties to promote wound epithelization. In this study, a novel nitric oxide-generated wound dressing based on an amniotic membrane was investigated. This construct consisted of a chitosan/β-glycerophosphate thermosensitive hydrogel covered with a decellularized human amniotic layer embedded with GSNO-loaded polylactic acid microparticles. The structure of GSNO was confirmed by spectrometric, elemental, and chemical analyses. The GSNO-loaded microparticles had a diameter of 40.66 ± 6.92 µm, and an encapsulation efficiency of 45.6 ± 6.74%. The hybrid construct and GSNO-loaded microparticles enhanced the long-term stable release of GSNO compared to free GSNO. The construct released nitric oxide ranging from 24 to 68 nM/mg during 7 days. The thermosensitive hydrogel was formed at 32.7 ± 1 °C and had a porous structure with a pore size of 41.76 ± 9.76 µm. The MTT and live/dead assays performed on human dermal fibroblast cells demonstrated suitable cell viability and adhesion to the final construct. Further, hemolysis analysis revealed less than a 5% hemolysis rate due to negligible blood cell adhesion. Overall, the prepared hybrid construct demonstrated suitable characteristics as a potential active wound dressing capable of controlled nitric oxide delivery.

In recent years, injectable hydrogels and cardiac patches have provided a promising approach to improve cardiac regeneration and function after myocardial infarction, however, the crucial designing factors of these biomaterials have been less reviewed. Therefore, in this review, we speculate on the prominent design parameters. A profound understanding of the main properties of native heart tissue can guide the efforts to obtain biomaterials with desirable biomimicking properties that improve the effectiveness of future fabricated myocardial biomaterials. Moreover, the injectable hydrogels and cardiac patches with reactive oxygen species scavenging properties will be reviewed in detail owing to the promising results of in vitro and in vivo studies on cardiac regeneration after myocardial infarction. This review can pave the way for an optimized design for effective cardiac biomaterials by considering the optimum ranges for physical, chemical, and biological characteristics of biomaterials, as well as the study of undetected parameters that can be investigated in future studies.

Polyaniline (PANI) was in-situ polymerized on nanofibrous polycaprolactone mats as cell-free antioxidant cardiac patches (CPs), providing electrical conductivity and antioxidant properties. The fabricated CPs took advantage of intrinsic and additive antioxidant properties in the presence of PANI backbone and ascorbic acid as a biocompatible dopant of PANI. The antioxidant nature of CPs may reduce the serious repercussions of oxidative stress, produced during the ischemia-reperfusion (I/R) process following myocardial infarction. The polymerization parameters were considered as aniline (60 mM, 90 mM, and 120 mM), ascorbic acid concentrations ([aniline]:[ascorbic acid] = 3:0, 3:0.5, 3:1, 3:3), and polymerization time (1 h and 3 h). Mainly, the more aniline concentrations and polymerization time, the less sheet resistance was obtained. 1,1 diphenyl-2-picrylhydrazyl (DPPH) assay confirmed the dual antioxidant properties of prepared samples. The advantage of the employed in-situ polymerization was confirmed by the de-doping/re-doping process. Non-desirable groups were excluded based on their electrical conductivity, antioxidant properties, and biocompatibility. The remained groups protected H9c2 cells against oxidative stress and hypoxia conditions. Selected CPs reduced the intracellular reactive oxygen species content and mRNA level of caspase-3 while the Bcl-2 mRNA level was improved. Also, the selected cardiac patch could attenuate the hypertrophic impact of hydrogen peroxide on H9c2 cells. The in vivo results of the skin flap model confirmed the CP potency to attenuate the harmful impact of I/R.

Engineering functional bone tissue requires scaffolds that can mimic the natural cellular environment, providing mechanical, electrical, and biochemical stimuli. This study introduces polyaniline (PANI)-based nanofibers for bone tissue engineering, utilizing electrospinning and ascorbic acid (AA) as a biocompatible dopant to replace camphorsulphonic acid (CSA), addressing cytotoxicity. The scaffolds' morphology, conductivity, chemical composition, drug release, hydrophilicity, and cytotoxicity were assessed through various techniques. Incorporating PANI and AA into poly(L-lactide) decreased the nanofibers' diameter, attributed to AA's role as a dopant enhancing PANI's conductivity, thereby increasing the charge density in the electrospinning solution. Scaffolds' conductivity measured via the two-point probe method, and its amount in the PANI-AA scaffold was 2.5 × 10⁻6 S within the range of body conductivity. The presence of PANI in the nanofibers was confirmed by ATR-FTIR and EDX spectroscopy. The release of AA from the scaffolds over 14 days was monitored by UV-Visible spectroscopy. It was found that the drug release followed a diffusion-controlled mechanism. Furthermore, the inclusion of AA in the scaffolds led to increased hydrophilicity, primarily due to the presence of hydroxyl groups within the AA molecular structure. Evaluation with the osteoblast cell line revealed superior cell growth, adhesion, and ossification in the drug-containing scaffolds. Among all groups, the scaffold containing the drug exhibited the greatest level of calcium deposition and the highest alkaline phosphatase enzyme activity. These findings highlight the potential of the AA-doped PANI scaffold for bone tissue engineering, offering a promising approach for the development of advanced biomaterials in regenerative medicine.

Increasing evidence indicates that engineered nerve grafts have great potential for the regeneration of peripheral nerve injuries(PNIs).While most studies have focused only on the topographical features of the grafts,we have considered both the biophys-ical and biochemical manipulations in our applied nanoscaffold.To achieve this,we fabricated an electrospun nanofibrous scaffold(ENS)containing polylactide nanofibers loaded with lithium(Li)ions,a Wnt/β-catenin signaling activator.In addi-tion,we seeded human adipose-derived mesenchymal stem cells(hADMSCs)onto this engineered scaffold to examine if their differentiation toward Schwann-like cells was induced.We further examined the efficacy of the scaffolds for nerve regeneration in vivo via grafting in a PNI rat model.Our results showed that Li-loaded ENSs gradually released Li within 11 d,at concentrations ranging from 0.02 to(3.64±0.10)mmol/L,and upregulated the expression of Wnt/β-catenin target genes(cyclinD1 and c-Myc)as well as those of Schwann cell markers(growth-associated protein 43(GAP43),S100 calcium binding protein B(S100B),glial fibrillary acidic protein(GFAP),and SRY-box transcription factor 10(SOX 10))in differ-entiated hADMSCs.In the PNI rat model,implantation of Li-loaded ENSs with/without cells improved behavioral features such as sensory and motor functions as well as the electrophysiological characteristics of the injured nerve.This improved function was further validated by histological analysis of sciatic nerves grafted with Li-loaded ENSs,which showed no fibrous connective tissue but enhanced organized myelinated axons.The potential of Li-loaded ENSs in promoting Schwann cell differentiation of hADMSCs and axonal regeneration of injured sciatic nerves suggests their potential for application in peripheral nerve tissue engineering.

Uninterrupted microscopic observation and real-time imaging of cell behavior during exposure to the stimulus, for example, electric and/or magnetic fields, especially for periods of several days, has been a challenge in experimental bioelectromagnetics due to a lack of proper gas/temperature conditions outside the incubator. Conventional mini-incubators might suffer from stray fields produced by heating elements. We report an in vitro electric and magnetic fields (EMF) exposure system embedded inside a novel under-the-microscope mini-CO2 -incubator with a unique design to avoid electromagnetic interference from the heating and circulation functions while ensuring the requisite temperature. A unique, reconfigurable array of electrodes and/or coils excited by calculated current distributions among array elements is designed to provide excellent field uniformity and controllable linear or circular polarization (even at very low frequencies) of the EMF within the cell culture. Using standard biochemical assays, long-term cell viability has been verified and compared with a conventional incubator. Cell orientation/migration in three-dimensional culture made of collagen-hydrogels has been successfully observed in vitro, in long-term, and in real-time under the influence of DC electric fields with the device.

Cell-based therapies of the peripheral nerve injury (PNI) have provided satisfactory outcomes among which Schwann cells (SCs) are the most reliable candidate to improve repair of the damaged nerve, however, it is difficult to obtain sufficient amount of SCs for clinical applications. Trabecular meshwork-derived mesenchymal stem cells (TM-MSCs) are newly introduced neural crest originated MSCs, which may have a desirable potential for Schwann-like differentiation due to their common lineage. On the other hand, one of the challenges of cell-based therapies is usage of serum containing media which is inappropriate for clinical applications. In the present study, we investigated the differentiation potential of TM-MSCs into Schwann-like cells on polylactide (PLA) nanofibrous scaffolds in the presence or absence of serum. Our results revealed that PLA nanofibers had no negative effects on the cell growth and proliferation of TM-MSCs, and improved Schwann-like differentiation compared with tissue culture plates (TCPs). More importantly, when the cells cultured on the scaffold in the presence of serum-free media (SFM), expression mRNA levels of SC markers (S100B, GAP43, GFAP and SOX10) were significantly increased compared with those of serum-rich groups. Immunostaining of TM-MSCs cultured on serum-free PLA nanofibrous scaffolds also showed significant expression of GAP43, GFAP and SOX10 compared to those of control, indicating the efficient role of SFM in the differentiation of TM-MSCs into SCs lineage. Overall, the findings of this study revealed the differentiation potential of TM-MSCs to SC fate for the first time, and also showed the beneficial effects of SFM and PLA nanofibrous scaffolds as a promising approach for peripheral nerve regeneration.

The challenge of restoration from neurodegenerative disorder requires effective solutions. To enhance the healing efficiencies, scaffolds with antioxidant activities, electroconductivity, and versatile features to encourage neuronal differentiation are potentially useful. Herein, polypyrrole-alginate (Alg-PPy) copolymer was used to design antioxidant and electroconductive hydrogels through the chemical oxidation radical polymerization method. The hydrogels have antioxidant effects to combat oxidative stress in nerve damage thanks to the introduction of PPy. Additionally, poly-l-lysine (PLL) provided these hydrogels with a great differentiation ability of stem cells. The morphology, porosity, swelling ratio, antioxidant activity, rheological behavior, and conductive characteristics of these hydrogels were precisely adjusted by altering the amount of PPy. Characterization of hydrogels showed appropriate electrical conductivity and antioxidant activity for neural tissue applications. Cytocompatibility, live/dead assays, and Annexin V/PI staining by flow cytometry using P19 cells confirmed the excellent cytocompatibility and cell protective effect under ROS microenvironment of these hydrogels in both normal and oxidative conditions. The neural marker investigation in the induction of electrical impulses was assessed through RT-PCR and immunofluorescence assay, demonstrating the differentiation of P19 cells to neurons cultured in these scaffolds. In summary, the antioxidant and electroconductive Alg-PPy/PLL hydrogels demonstrated excellent potential as promising scaffolds for treating neurodegenerative disorders.

Due to the challenges related to the cytotoxicity of polyaniline (PANI), tissue engineering applications of PANI-coated nanofibers are limited. For this reason, PANI-based nanofibers are usually made through the blending of PANI and biocompatible polymers to reduce the cytotoxicity of the final scaffold. In the present study, PANI-coated nanofibers with no cytotoxic effects were prepared. Two types of PANI-coated nanofibers with different dopants including hydrochloric acid (HCl) and taurine (Tau) were fabricated, characterized, and compared to introduce a conductive scaffold with no cytotoxicity. In fact, Tau as a bioactive dopant was used to enhance the biocompatibility of PANI-coated nanofibers. To this end, plasma-treated poly(ethersulfone) (PES) electrospun nanofibers were used as the template. Then, the PANI-coated nanofibers were fabricated via in situ chemical oxidative polymerization of PANI-HCl and PANI-Tau. The PANI-coated nanofibers were assessed by microscopy, infrared spectroscopy, porosity analysis, conductivity analysis, contact angle measurement, and indirect MTT assay to ascertain the effects of dopants on the properties of the nanofibers. Severe cytotoxicity was observed in the extraction of the PES/PANI-HCl nanofibers, while the extraction of PES/PANI-Tau nanofibers enhanced cell viability. On the other hand, between PANI-HCl and PANI-Tau, the first compound had higher conductivity while the second one had higher conductivity stability in the cell culture medium. With respect to the biocompatibility and physicochemical properties of the above-mentioned nanofibers, Tau-doped-PANI-coated nanofibers could be considered as a novel biocompatible conductive scaffold for tissue engineering applications.

Between conductive polymers, polyaniline (PANI) has elicited much interest among researchers, but one of its issues for biological applications is cytotoxicity and conductivity reduction due to dopant separation. The purpose of this study is to prepare nylon nanofibers by electrospinning and coating them with self-doped PANI to improve the stability of its conductivity without any cytotoxicity. For this purpose, the self-doped copolymer containing aniline/metanilic acid was coated on the nylon nanofibers and its conductivity was compared with hydrochloric acid (HCL)-doped PANI. It was shown that, the conductivity of HCL-doped PANI decreased dramatically with time; The conductivity on the first day was 6.1×10 -6 S/cm and, it reached 11.2×10 -9 S/cm after 7 days of immersion in PBS. On the contrary, the conductivity of nanofibers coated with aniline/metanilic acid with ratios of 1:1 and 3:1 was 9.7×10 -9 S/cm and 11.3×10 -9 S/cm, respectively. But the conductivity of the self-doped scaffolds was stable and reached to 8.8×10 -9 S/cm and 9.4×10 -9 S/cm during 7 days. The conductive scaffold prepared in this research will have a high potential for biomedical engineering applications, especially tissue engineering and biosensors.

The subject of this paper is to develop a highly conductive Graphene nanoplatelets (GNPs)-Chitosan (CS)/Polyvinyl Alcohol (PVA) (GNPs-CP) nanofibers with excellent mechanical properties. An experimental study was designed to produce nanofibers based on CP nanofibers as matrix and GNPs as reinforcement materials. The microstructure and the surface morphology of the electrospun nanofibers along with their electrical and mechanical properties were examined to study the effect of GNPs content. The SEM results showed that the gradual increase in GNPs content led to a porous web like morphology with no bead. There is a decrease in the diameter of nanofibers by increasing the concentration of GNPs to 1 wt% GNPs from 370 ± 40 nm for CP blend to 144 ± 18 nm for 1 wt% GNPs. Transmission electron microscopy results depicted that GNPs were dispersed uniformly confirmed by the absence of characteristic peak of graphite at 2θ = 26.5°. Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy results indicate the occurrence of a few interactions between GNPs and CP matrix. Nitrogen adsorption/desorption measurement demonstrated that increasing GNPs content increased the specific surface area of nanofibers from 238.377 to 386.708 m2/g for 0 and 1 wt% GNPs content. The test results also show that the presence of GNPs considerably enhances tensile strength, elastic modulus and electrical conductivity. Furthermore, the toughness of GNPs-CP nanofibers including 1 wt% GNPs significantly improved (12-fold) compared to the one for CP nanofibers. So, the proposed composite provides a decent functionality for nanofibers as scaffolds in tissue engineering applications.

Neuronal differentiation from stem cells is one of the most potent therapeutic approaches for recovering neurological function in individuals with neurodegenerative disorders. Herein, an on-demand intracellular retinoic acid released nanoparticles with tunable size and accurately controlled physico-biological properties have been prepared for achieving efficient neuronal differentiation. The amphiphilic chitosan oligosaccharide-cholesterol copolymers were synthesized by varying cholesterol content and self-assembled into spherical micelle in a microfluidic chip with different flow rates. Notably, the results indicated that by increasing the lipophilicity of the chitosan chain as well as mixing rate, the size of micelles was decreased. Retinoic acid (RA) was efficiently encapsulated in the core of micelles. The retinoic acid-containing nanoparticles could escape lysosome, accumulate in the cytoplasm, and release payload with a sustained pattern. The cytotoxicity assay of free retinoic acid and retinoic acid-loaded formulations against P19 embryonic stem cells confirmed the desirable safety of micelles. The result obtained from the uptake study showed that internalization of micelles occurs predominantly via lipid-raft endocytosis in the presence of higher cholesterol content. Moreover, the intracellular RA release upregulated the expression levels of neuronal factors. The micelles described here offer a promising nanomedicine strategy for neuronal differentiation of stem cells.

Self-healing is a significant characteristic of living tissues through repair or regeneration that prevents the accumulation of defects due to tissue aging and fatigue. Use of self-healing polymers (SHPs) that can recover their functionality in the dynamic environment of the human body is an exciting biomimetic approach for designing a new generation of biomaterials. SHPs increase the durability and reliability of the biomedical devices and reduce the waste of resources. In this article, healing mechanisms in SHP-based biomaterials, their biocompatibility, and their biomedical applications including tissue engineering, cell/drug delivery, implants, biosensors, bioadhesives, and wound dressings are reviewed.

One of the main challenges of using polyaniline (PANI) in tissue engineering, is the cytotoxicity of PANI dopants, which compromises their biocompatibility. Herein, we aimed to substitute a biocompatible dopant instead of other cytotoxic dopants such as, camphor sulfonic acid (CSA). For this purpose, poly-L-lactic acid (PLLA) was used as a carrier polymer, PANI as a conductive agent, and AA as a biological factor and PANI dopant. Conductive scaffolds were fabricated via electrospinning. Finally, the morphology of the scaffolds was evaluated using a scanning electron microscope (SEM). By adding PANI, CSA and AA dopants to PLLA, we observed a decrease in the diameter of nanofibers from 841 ± 181 nm to 468 ± 62 nm and from 841 ± 181 nm to 546 ± 77 nm, respectively. The conductivity of the scaffolds was measured by the two-point probe, which was 9.7 × 10–5 in the PANI-CSA scaffold and 4 × 10–5 in the PANI-AA scaffold. Considering that the acidity of CSA is higher than the acidity of AA, its polymer solution has more conductivity and leads to a decrease in the diameter of nanofibers. Therefore, we proposed that PANI-AA-based nanofibers can be used as a bioactive conductive scaffold for bone tissue engineering. Since AA does not have the cytotoxicity of CSA and in addition to playing a biological role that causes bone differentiation, it also has the role of a dopant for PANI.